diff --git a/.gitignore b/.gitignore
index 5d46fe1..4197c8c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -127,4 +127,10 @@ dmypy.json
 .pyre/
 
 .DS_Store
-config.ini
\ No newline at end of file
+
+*.ini
+
+.antlr
+antlr*.jar
+
+*.code-workspace
\ No newline at end of file
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..25cf19b
--- /dev/null
+++ b/README.md
@@ -0,0 +1,14 @@
+# Prerequest
+
+- Install dependencies:
+
+```sh
+python3 install -r packages.txt
+```
+
+# Neo4j client library
+
+Whole infrastructure to develop client library is placed in the `db` folder. This folder contains [README](db/README.md) file with more information.
+
+# Web
+
diff --git a/db/README.md b/db/README.md
new file mode 100644
index 0000000..74065fb
--- /dev/null
+++ b/db/README.md
@@ -0,0 +1,14 @@
+## Development
+
+- Run neo4j is a requirement to run code in development process. [Run official docker](https://neo4j.com/developer/docker/) is easiest way to do that.
+
+- Create configuration file `config.ini`. See [config.ini](db/config.ini)
+
+## Codestlye
+
+- Please style your code aacording to [PEP8](https://www.python.org/dev/peps/pep-0008/) rules
+
+## Regenerate ANTLR parser
+
+- [Download](https://www.antlr.org/download.html) antlr generator.
+- Run generation script `./scripts/generate_antlr.sh antlr-4.9.2-complete.jar`
\ No newline at end of file
diff --git a/db/sc/__init__.py b/db/sc/__init__.py
index c1e63ed..bfa57e7 100644
--- a/db/sc/__init__.py
+++ b/db/sc/__init__.py
@@ -1 +1,2 @@
 from sc.memory import Memory
+from sc.scs import SCsParser
diff --git a/db/sc/core/keynodes.py b/db/sc/core/keynodes.py
index ad87904..30c912b 100644
--- a/db/sc/core/keynodes.py
+++ b/db/sc/core/keynodes.py
@@ -1,3 +1,39 @@
-class Keynodes:
+class KeynodeNames:
+    SC_NODE = "sc_node"
+    SC_LINK = "sc_link"
+    SC_EDGE = "sc_edge"
+    SC_ARC = "sc_arc"
 
+    CORE_TYPES = [SC_NODE, SC_LINK, SC_EDGE, SC_ARC]
+
+    SC_CONST = "sc_const"
+    SC_VAR = "sc_var"
+
+    CONST_TYPES = [SC_CONST, SC_VAR]
+
+    SC_NODE_STRUCT = "sc_node_struct"
+    SC_NODE_TUPLE = "sc_node_tuple"
+    SC_NODE_ROLE = "sc_node_role"
+    SC_NODE_NO_ROLE = "sc_node_no_role"
+    SC_NODE_CLASS = "sc_node_class"
+    SC_NODE_ABSTRACT = "sc_node_abstract"
+    SC_NODE_MATERIAL = "sc_node_material"
+
+    NODE_TYPES = [
+        SC_NODE_STRUCT, SC_NODE_TUPLE, SC_NODE_ROLE,
+        SC_NODE_NO_ROLE, SC_NODE_CLASS, SC_NODE_ABSTRACT,
+        SC_NODE_MATERIAL]
+
+    SC_ARC_PERM = "sc_arc_perm"
+    SC_ARC_TEMP = "sc_arc_temp"
+
+    ARC_PERM_TYPES = [SC_ARC_PERM, SC_ARC_TEMP]
+
+    SC_ARC_POS = "sc_arc_pos"
+    SC_ARC_NEG = "sc_arc_neg"
+    SC_ARC_FUZ = "sc_arc_fuz"
+
+    ARC_POS_TYPES = [SC_ARC_POS, SC_ARC_NEG, SC_ARC_FUZ]
+
+    # common keynodes
     NREL_SYS_IDTF = "nrel_system_identifier"
diff --git a/db/sc/core/transaction/names.py b/db/sc/core/transaction/names.py
index fe82e43..74b48ac 100644
--- a/db/sc/core/transaction/names.py
+++ b/db/sc/core/transaction/names.py
@@ -1,5 +1,5 @@
 from sc.core.element import Element
-from sc.core.keynodes import Keynodes
+from sc.core.keynodes import KeynodeNames
 from sc.core.keywords import Labels, TypeAttrs
 from sc.core.transaction.utils import _parse_output_element, _get_label_from_type
 
@@ -32,7 +32,7 @@ class TransactionNamesWrite:
 
     def __init__(self,
                  driver: neo4j.Driver,
-                 nrel_sys_idtf: str = Keynodes.NREL_SYS_IDTF) -> None:
+                 nrel_sys_idtf: str = KeynodeNames.NREL_SYS_IDTF) -> None:
         self._driver = driver
         self._sys_idtfs = set()
         self._tasks = []
@@ -58,7 +58,7 @@ def _is_empty(self) -> bool:
         return len(self._sys_idtfs) == 0
 
     def _make_query(self) -> str:
-        query = (f"MATCH (l:{Labels.SC_LINK} {{content: '{Keynodes.NREL_SYS_IDTF}', {_const_attr()} }})"
+        query = (f"MATCH (l:{Labels.SC_LINK} {{content: '{KeynodeNames.NREL_SYS_IDTF}', {_const_attr()} }})"
                  f"<-[__idtf_edge:{Labels.SC_ARC} {{ {TypeAttrs.CONST}: 'CONST' }}]"
                  f"-(__sys_idtf:{Labels.SC_NODE}), \n"
                  f"(:{Labels.SC_EDGE_SOCK} {{edge_id: id(__idtf_edge)}})"
@@ -136,7 +136,7 @@ class TransactionNamesRead:
 
     def __init__(self,
                  driver: neo4j.Driver,
-                 nrel_sys_idtf: str = Keynodes.NREL_SYS_IDTF) -> None:
+                 nrel_sys_idtf: str = KeynodeNames.NREL_SYS_IDTF) -> None:
         self._driver = driver
         self._sys_idtfs = set()
 
@@ -161,7 +161,7 @@ def _is_empty(self) -> bool:
 
     def _make_query(self) -> str:
 
-        query = (f"MATCH (l:{Labels.SC_LINK} {{ content: '{Keynodes.NREL_SYS_IDTF}', {_const_attr()} }})"
+        query = (f"MATCH (l:{Labels.SC_LINK} {{ content: '{KeynodeNames.NREL_SYS_IDTF}', {_const_attr()} }})"
                  f"<-[edge:{Labels.SC_ARC} {{ {_const_attr()} }}]"
                  f"-(__sys_idtf:{Labels.SC_NODE}), \n"
                  f"(edge_sock:{Labels.SC_EDGE_SOCK} {{edge_id: id(edge)}})"
diff --git a/db/sc/memory.py b/db/sc/memory.py
index bc599fb..339513d 100644
--- a/db/sc/memory.py
+++ b/db/sc/memory.py
@@ -3,6 +3,7 @@
 from sc.core.transaction import TransactionWrite, TransactionRead, TransactionNamesWrite, TransactionNamesRead
 
 import neo4j
+import logging
 
 
 class Memory:
@@ -10,14 +11,14 @@ class Memory:
     def __init__(self, config_path: str):
         self._config = Config(config_path)
 
-        print(f"Connecting to {self._config.db_uri()}")
+        logging.info(f"Connecting to {self._config.db_uri()}")
         self._client = Client(
             self._config.db_uri(),
             self._config.db_user(),
             self._config.db_password())
 
     def close(self):
-        print(f"Close connection to {self._config.db_uri()}")
+        logging.info(f"Close connection to {self._config.db_uri()}")
         self._client.close()
 
     @property
diff --git a/db/sc/scs/__init__.py b/db/sc/scs/__init__.py
new file mode 100644
index 0000000..1227a0d
--- /dev/null
+++ b/db/sc/scs/__init__.py
@@ -0,0 +1 @@
+from .parser import SCsParser
diff --git a/db/sc/scs/antlr/__init__.py b/db/sc/scs/antlr/__init__.py
new file mode 100644
index 0000000..3ee6fc2
--- /dev/null
+++ b/db/sc/scs/antlr/__init__.py
@@ -0,0 +1,2 @@
+from .scsLexer import scsLexer as SCsLexerAntlr
+from .scsParser import scsParser as SCsParserAntlr
diff --git a/db/sc/scs/antlr/scs.interp b/db/sc/scs/antlr/scs.interp
new file mode 100644
index 0000000..820edcc
--- /dev/null
+++ b/db/sc/scs/antlr/scs.interp
@@ -0,0 +1,155 @@
+token literal names:
+null
+'_'
+'<>'
+'<=>'
+'_<>'
+'_<=>'
+'>'
+'<'
+'=>'
+'<='
+'_=>'
+'_<='
+'..>'
+'<..'
+'->'
+'<-'
+'-|>'
+'<|-'
+'-/>'
+'</-'
+'~>'
+'<~'
+'~|>'
+'<|~'
+'~/>'
+'</~'
+'_..>'
+'_<..'
+'_->'
+'_<-'
+'_-|>'
+'_<|-'
+'_-/>'
+'_</-'
+'_~>'
+'_<~'
+'_~|>'
+'_<|~'
+'_~/>'
+'_</~'
+'...'
+'='
+'('
+')'
+';'
+'{'
+'}'
+'(*'
+'*)'
+null
+null
+'[*'
+'*]'
+null
+null
+null
+null
+null
+null
+null
+';;'
+
+token symbolic names:
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+ID_SYSTEM
+ALIAS_SYMBOLS
+CONTOUR_BEGIN
+CONTOUR_END
+CONTENT_BODY
+LINK
+EDGE_ATTR
+LINE_TERMINATOR
+LINE_COMMENT
+MULTINE_COMMENT
+WS
+SENTENCE_SEP
+
+rule names:
+content
+contour
+connector_edge
+connector_arc
+connector
+syntax
+sentence_wrap
+sentence
+ifdf_alias
+idtf_system
+sentence_assign
+idtf_edge
+idtf_set_item
+idtf_set_item_list
+idtf_set
+idtf_atomic
+idtf_url
+idtf_common
+idtf_list
+internal_sentence
+internal_sentence_list
+sentence_lvl_4_list_item
+sentence_lvl_common
+attr_list
+
+
+atn:
+[3, 24715, 42794, 33075, 47597, 16764, 15335, 30598, 22884, 3, 62, 226, 4, 2, 9, 2, 4, 3, 9, 3, 4, 4, 9, 4, 4, 5, 9, 5, 4, 6, 9, 6, 4, 7, 9, 7, 4, 8, 9, 8, 4, 9, 9, 9, 4, 10, 9, 10, 4, 11, 9, 11, 4, 12, 9, 12, 4, 13, 9, 13, 4, 14, 9, 14, 4, 15, 9, 15, 4, 16, 9, 16, 4, 17, 9, 17, 4, 18, 9, 18, 4, 19, 9, 19, 4, 20, 9, 20, 4, 21, 9, 21, 4, 22, 9, 22, 4, 23, 9, 23, 4, 24, 9, 24, 4, 25, 9, 25, 3, 2, 5, 2, 52, 10, 2, 3, 2, 3, 2, 3, 2, 3, 3, 3, 3, 3, 3, 3, 3, 7, 3, 61, 10, 3, 12, 3, 14, 3, 64, 11, 3, 3, 3, 3, 3, 3, 3, 3, 4, 3, 4, 3, 4, 3, 5, 3, 5, 3, 5, 3, 6, 3, 6, 3, 6, 3, 6, 3, 6, 3, 6, 5, 6, 81, 10, 6, 3, 7, 7, 7, 84, 10, 7, 12, 7, 14, 7, 87, 11, 7, 3, 7, 3, 7, 3, 8, 3, 8, 3, 8, 3, 9, 3, 9, 5, 9, 96, 10, 9, 3, 10, 3, 10, 3, 10, 3, 11, 3, 11, 3, 11, 3, 12, 3, 12, 3, 12, 3, 12, 3, 12, 3, 13, 3, 13, 3, 13, 3, 13, 5, 13, 113, 10, 13, 3, 13, 3, 13, 3, 13, 3, 13, 3, 14, 5, 14, 120, 10, 14, 3, 14, 3, 14, 3, 14, 3, 15, 3, 15, 3, 15, 7, 15, 128, 10, 15, 12, 15, 14, 15, 131, 11, 15, 3, 16, 3, 16, 3, 16, 3, 16, 3, 16, 3, 17, 3, 17, 3, 17, 3, 17, 3, 17, 3, 17, 5, 17, 144, 10, 17, 3, 18, 3, 18, 3, 18, 3, 19, 3, 19, 3, 19, 3, 19, 3, 19, 3, 19, 3, 19, 3, 19, 3, 19, 3, 19, 3, 19, 3, 19, 3, 19, 3, 19, 3, 19, 3, 19, 3, 19, 3, 19, 5, 19, 167, 10, 19, 3, 20, 3, 20, 3, 20, 5, 20, 172, 10, 20, 3, 20, 3, 20, 3, 20, 3, 20, 5, 20, 178, 10, 20, 7, 20, 180, 10, 20, 12, 20, 14, 20, 183, 11, 20, 3, 21, 3, 21, 5, 21, 187, 10, 21, 3, 21, 3, 21, 3, 21, 3, 22, 3, 22, 3, 22, 3, 22, 6, 22, 196, 10, 22, 13, 22, 14, 22, 197, 3, 22, 3, 22, 3, 23, 3, 23, 5, 23, 204, 10, 23, 3, 23, 3, 23, 3, 23, 3, 23, 3, 24, 3, 24, 3, 24, 3, 24, 7, 24, 214, 10, 24, 12, 24, 14, 24, 217, 11, 24, 3, 25, 3, 25, 3, 25, 6, 25, 222, 10, 25, 13, 25, 14, 25, 223, 3, 25, 2, 2, 26, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 2, 5, 3, 2, 4, 13, 3, 2, 14, 41, 4, 2, 42, 42, 51, 51, 2, 223, 2, 51, 3, 2, 2, 2, 4, 56, 3, 2, 2, 2, 6, 68, 3, 2, 2, 2, 8, 71, 3, 2, 2, 2, 10, 80, 3, 2, 2, 2, 12, 85, 3, 2, 2, 2, 14, 90, 3, 2, 2, 2, 16, 95, 3, 2, 2, 2, 18, 97, 3, 2, 2, 2, 20, 100, 3, 2, 2, 2, 22, 103, 3, 2, 2, 2, 24, 108, 3, 2, 2, 2, 26, 119, 3, 2, 2, 2, 28, 124, 3, 2, 2, 2, 30, 132, 3, 2, 2, 2, 32, 143, 3, 2, 2, 2, 34, 145, 3, 2, 2, 2, 36, 166, 3, 2, 2, 2, 38, 168, 3, 2, 2, 2, 40, 184, 3, 2, 2, 2, 42, 191, 3, 2, 2, 2, 44, 201, 3, 2, 2, 2, 46, 209, 3, 2, 2, 2, 48, 221, 3, 2, 2, 2, 50, 52, 7, 3, 2, 2, 51, 50, 3, 2, 2, 2, 51, 52, 3, 2, 2, 2, 52, 53, 3, 2, 2, 2, 53, 54, 7, 55, 2, 2, 54, 55, 8, 2, 1, 2, 55, 3, 3, 2, 2, 2, 56, 57, 7, 53, 2, 2, 57, 58, 6, 3, 2, 2, 58, 62, 8, 3, 1, 2, 59, 61, 5, 14, 8, 2, 60, 59, 3, 2, 2, 2, 61, 64, 3, 2, 2, 2, 62, 60, 3, 2, 2, 2, 62, 63, 3, 2, 2, 2, 63, 65, 3, 2, 2, 2, 64, 62, 3, 2, 2, 2, 65, 66, 7, 54, 2, 2, 66, 67, 8, 3, 1, 2, 67, 5, 3, 2, 2, 2, 68, 69, 9, 2, 2, 2, 69, 70, 8, 4, 1, 2, 70, 7, 3, 2, 2, 2, 71, 72, 9, 3, 2, 2, 72, 73, 8, 5, 1, 2, 73, 9, 3, 2, 2, 2, 74, 75, 5, 6, 4, 2, 75, 76, 8, 6, 1, 2, 76, 81, 3, 2, 2, 2, 77, 78, 5, 8, 5, 2, 78, 79, 8, 6, 1, 2, 79, 81, 3, 2, 2, 2, 80, 74, 3, 2, 2, 2, 80, 77, 3, 2, 2, 2, 81, 11, 3, 2, 2, 2, 82, 84, 5, 14, 8, 2, 83, 82, 3, 2, 2, 2, 84, 87, 3, 2, 2, 2, 85, 83, 3, 2, 2, 2, 85, 86, 3, 2, 2, 2, 86, 88, 3, 2, 2, 2, 87, 85, 3, 2, 2, 2, 88, 89, 7, 2, 2, 3, 89, 13, 3, 2, 2, 2, 90, 91, 5, 16, 9, 2, 91, 92, 7, 62, 2, 2, 92, 15, 3, 2, 2, 2, 93, 96, 5, 22, 12, 2, 94, 96, 5, 46, 24, 2, 95, 93, 3, 2, 2, 2, 95, 94, 3, 2, 2, 2, 96, 17, 3, 2, 2, 2, 97, 98, 7, 52, 2, 2, 98, 99, 8, 10, 1, 2, 99, 19, 3, 2, 2, 2, 100, 101, 9, 4, 2, 2, 101, 102, 8, 11, 1, 2, 102, 21, 3, 2, 2, 2, 103, 104, 7, 52, 2, 2, 104, 105, 7, 43, 2, 2, 105, 106, 5, 36, 19, 2, 106, 107, 8, 12, 1, 2, 107, 23, 3, 2, 2, 2, 108, 109, 7, 44, 2, 2, 109, 110, 5, 32, 17, 2, 110, 112, 5, 10, 6, 2, 111, 113, 5, 48, 25, 2, 112, 111, 3, 2, 2, 2, 112, 113, 3, 2, 2, 2, 113, 114, 3, 2, 2, 2, 114, 115, 5, 32, 17, 2, 115, 116, 7, 45, 2, 2, 116, 117, 8, 13, 1, 2, 117, 25, 3, 2, 2, 2, 118, 120, 5, 48, 25, 2, 119, 118, 3, 2, 2, 2, 119, 120, 3, 2, 2, 2, 120, 121, 3, 2, 2, 2, 121, 122, 5, 36, 19, 2, 122, 123, 8, 14, 1, 2, 123, 27, 3, 2, 2, 2, 124, 129, 5, 26, 14, 2, 125, 126, 7, 46, 2, 2, 126, 128, 5, 26, 14, 2, 127, 125, 3, 2, 2, 2, 128, 131, 3, 2, 2, 2, 129, 127, 3, 2, 2, 2, 129, 130, 3, 2, 2, 2, 130, 29, 3, 2, 2, 2, 131, 129, 3, 2, 2, 2, 132, 133, 7, 47, 2, 2, 133, 134, 8, 16, 1, 2, 134, 135, 5, 28, 15, 2, 135, 136, 7, 48, 2, 2, 136, 31, 3, 2, 2, 2, 137, 138, 5, 18, 10, 2, 138, 139, 8, 17, 1, 2, 139, 144, 3, 2, 2, 2, 140, 141, 5, 20, 11, 2, 141, 142, 8, 17, 1, 2, 142, 144, 3, 2, 2, 2, 143, 137, 3, 2, 2, 2, 143, 140, 3, 2, 2, 2, 144, 33, 3, 2, 2, 2, 145, 146, 7, 56, 2, 2, 146, 147, 8, 18, 1, 2, 147, 35, 3, 2, 2, 2, 148, 149, 5, 32, 17, 2, 149, 150, 8, 19, 1, 2, 150, 167, 3, 2, 2, 2, 151, 152, 5, 24, 13, 2, 152, 153, 8, 19, 1, 2, 153, 167, 3, 2, 2, 2, 154, 155, 5, 30, 16, 2, 155, 156, 8, 19, 1, 2, 156, 167, 3, 2, 2, 2, 157, 158, 5, 4, 3, 2, 158, 159, 8, 19, 1, 2, 159, 167, 3, 2, 2, 2, 160, 161, 5, 2, 2, 2, 161, 162, 8, 19, 1, 2, 162, 167, 3, 2, 2, 2, 163, 164, 5, 34, 18, 2, 164, 165, 8, 19, 1, 2, 165, 167, 3, 2, 2, 2, 166, 148, 3, 2, 2, 2, 166, 151, 3, 2, 2, 2, 166, 154, 3, 2, 2, 2, 166, 157, 3, 2, 2, 2, 166, 160, 3, 2, 2, 2, 166, 163, 3, 2, 2, 2, 167, 37, 3, 2, 2, 2, 168, 169, 5, 36, 19, 2, 169, 171, 8, 20, 1, 2, 170, 172, 5, 42, 22, 2, 171, 170, 3, 2, 2, 2, 171, 172, 3, 2, 2, 2, 172, 181, 3, 2, 2, 2, 173, 174, 7, 46, 2, 2, 174, 175, 5, 36, 19, 2, 175, 177, 8, 20, 1, 2, 176, 178, 5, 42, 22, 2, 177, 176, 3, 2, 2, 2, 177, 178, 3, 2, 2, 2, 178, 180, 3, 2, 2, 2, 179, 173, 3, 2, 2, 2, 180, 183, 3, 2, 2, 2, 181, 179, 3, 2, 2, 2, 181, 182, 3, 2, 2, 2, 182, 39, 3, 2, 2, 2, 183, 181, 3, 2, 2, 2, 184, 186, 5, 10, 6, 2, 185, 187, 5, 48, 25, 2, 186, 185, 3, 2, 2, 2, 186, 187, 3, 2, 2, 2, 187, 188, 3, 2, 2, 2, 188, 189, 5, 38, 20, 2, 189, 190, 8, 21, 1, 2, 190, 41, 3, 2, 2, 2, 191, 195, 7, 49, 2, 2, 192, 193, 5, 40, 21, 2, 193, 194, 7, 62, 2, 2, 194, 196, 3, 2, 2, 2, 195, 192, 3, 2, 2, 2, 196, 197, 3, 2, 2, 2, 197, 195, 3, 2, 2, 2, 197, 198, 3, 2, 2, 2, 198, 199, 3, 2, 2, 2, 199, 200, 7, 50, 2, 2, 200, 43, 3, 2, 2, 2, 201, 203, 5, 10, 6, 2, 202, 204, 5, 48, 25, 2, 203, 202, 3, 2, 2, 2, 203, 204, 3, 2, 2, 2, 204, 205, 3, 2, 2, 2, 205, 206, 5, 38, 20, 2, 206, 207, 3, 2, 2, 2, 207, 208, 8, 23, 1, 2, 208, 45, 3, 2, 2, 2, 209, 210, 5, 36, 19, 2, 210, 215, 5, 44, 23, 2, 211, 212, 7, 46, 2, 2, 212, 214, 5, 44, 23, 2, 213, 211, 3, 2, 2, 2, 214, 217, 3, 2, 2, 2, 215, 213, 3, 2, 2, 2, 215, 216, 3, 2, 2, 2, 216, 47, 3, 2, 2, 2, 217, 215, 3, 2, 2, 2, 218, 219, 7, 51, 2, 2, 219, 220, 7, 57, 2, 2, 220, 222, 8, 25, 1, 2, 221, 218, 3, 2, 2, 2, 222, 223, 3, 2, 2, 2, 223, 221, 3, 2, 2, 2, 223, 224, 3, 2, 2, 2, 224, 49, 3, 2, 2, 2, 20, 51, 62, 80, 85, 95, 112, 119, 129, 143, 166, 171, 177, 181, 186, 197, 203, 215, 223]
\ No newline at end of file
diff --git a/db/sc/scs/antlr/scs.tokens b/db/sc/scs/antlr/scs.tokens
new file mode 100644
index 0000000..6aebcb7
--- /dev/null
+++ b/db/sc/scs/antlr/scs.tokens
@@ -0,0 +1,111 @@
+T__0=1
+T__1=2
+T__2=3
+T__3=4
+T__4=5
+T__5=6
+T__6=7
+T__7=8
+T__8=9
+T__9=10
+T__10=11
+T__11=12
+T__12=13
+T__13=14
+T__14=15
+T__15=16
+T__16=17
+T__17=18
+T__18=19
+T__19=20
+T__20=21
+T__21=22
+T__22=23
+T__23=24
+T__24=25
+T__25=26
+T__26=27
+T__27=28
+T__28=29
+T__29=30
+T__30=31
+T__31=32
+T__32=33
+T__33=34
+T__34=35
+T__35=36
+T__36=37
+T__37=38
+T__38=39
+T__39=40
+T__40=41
+T__41=42
+T__42=43
+T__43=44
+T__44=45
+T__45=46
+T__46=47
+T__47=48
+ID_SYSTEM=49
+ALIAS_SYMBOLS=50
+CONTOUR_BEGIN=51
+CONTOUR_END=52
+CONTENT_BODY=53
+LINK=54
+EDGE_ATTR=55
+LINE_TERMINATOR=56
+LINE_COMMENT=57
+MULTINE_COMMENT=58
+WS=59
+SENTENCE_SEP=60
+'_'=1
+'<>'=2
+'<=>'=3
+'_<>'=4
+'_<=>'=5
+'>'=6
+'<'=7
+'=>'=8
+'<='=9
+'_=>'=10
+'_<='=11
+'..>'=12
+'<..'=13
+'->'=14
+'<-'=15
+'-|>'=16
+'<|-'=17
+'-/>'=18
+'</-'=19
+'~>'=20
+'<~'=21
+'~|>'=22
+'<|~'=23
+'~/>'=24
+'</~'=25
+'_..>'=26
+'_<..'=27
+'_->'=28
+'_<-'=29
+'_-|>'=30
+'_<|-'=31
+'_-/>'=32
+'_</-'=33
+'_~>'=34
+'_<~'=35
+'_~|>'=36
+'_<|~'=37
+'_~/>'=38
+'_</~'=39
+'...'=40
+'='=41
+'('=42
+')'=43
+';'=44
+'{'=45
+'}'=46
+'(*'=47
+'*)'=48
+'[*'=51
+'*]'=52
+';;'=60
diff --git a/db/sc/scs/antlr/scsLexer.interp b/db/sc/scs/antlr/scsLexer.interp
new file mode 100644
index 0000000..101ffb8
--- /dev/null
+++ b/db/sc/scs/antlr/scsLexer.interp
@@ -0,0 +1,200 @@
+token literal names:
+null
+'_'
+'<>'
+'<=>'
+'_<>'
+'_<=>'
+'>'
+'<'
+'=>'
+'<='
+'_=>'
+'_<='
+'..>'
+'<..'
+'->'
+'<-'
+'-|>'
+'<|-'
+'-/>'
+'</-'
+'~>'
+'<~'
+'~|>'
+'<|~'
+'~/>'
+'</~'
+'_..>'
+'_<..'
+'_->'
+'_<-'
+'_-|>'
+'_<|-'
+'_-/>'
+'_</-'
+'_~>'
+'_<~'
+'_~|>'
+'_<|~'
+'_~/>'
+'_</~'
+'...'
+'='
+'('
+')'
+';'
+'{'
+'}'
+'(*'
+'*)'
+null
+null
+'[*'
+'*]'
+null
+null
+null
+null
+null
+null
+null
+';;'
+
+token symbolic names:
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+null
+ID_SYSTEM
+ALIAS_SYMBOLS
+CONTOUR_BEGIN
+CONTOUR_END
+CONTENT_BODY
+LINK
+EDGE_ATTR
+LINE_TERMINATOR
+LINE_COMMENT
+MULTINE_COMMENT
+WS
+SENTENCE_SEP
+
+rule names:
+T__0
+T__1
+T__2
+T__3
+T__4
+T__5
+T__6
+T__7
+T__8
+T__9
+T__10
+T__11
+T__12
+T__13
+T__14
+T__15
+T__16
+T__17
+T__18
+T__19
+T__20
+T__21
+T__22
+T__23
+T__24
+T__25
+T__26
+T__27
+T__28
+T__29
+T__30
+T__31
+T__32
+T__33
+T__34
+T__35
+T__36
+T__37
+T__38
+T__39
+T__40
+T__41
+T__42
+T__43
+T__44
+T__45
+T__46
+T__47
+ID_SYSTEM
+ALIAS_SYMBOLS
+CONTENT_ESCAPED
+CONTENT_SYBMOL
+CONTENT_SYBMOL_FIRST_END
+CONTOUR_BEGIN
+CONTOUR_END
+CONTENT_BODY
+LINK
+EDGE_ATTR
+LINE_TERMINATOR
+LINE_COMMENT
+MULTINE_COMMENT
+WS
+SENTENCE_SEP
+
+channel names:
+DEFAULT_TOKEN_CHANNEL
+HIDDEN
+
+mode names:
+DEFAULT_MODE
+
+atn:
+[3, 24715, 42794, 33075, 47597, 16764, 15335, 30598, 22884, 2, 62, 404, 8, 1, 4, 2, 9, 2, 4, 3, 9, 3, 4, 4, 9, 4, 4, 5, 9, 5, 4, 6, 9, 6, 4, 7, 9, 7, 4, 8, 9, 8, 4, 9, 9, 9, 4, 10, 9, 10, 4, 11, 9, 11, 4, 12, 9, 12, 4, 13, 9, 13, 4, 14, 9, 14, 4, 15, 9, 15, 4, 16, 9, 16, 4, 17, 9, 17, 4, 18, 9, 18, 4, 19, 9, 19, 4, 20, 9, 20, 4, 21, 9, 21, 4, 22, 9, 22, 4, 23, 9, 23, 4, 24, 9, 24, 4, 25, 9, 25, 4, 26, 9, 26, 4, 27, 9, 27, 4, 28, 9, 28, 4, 29, 9, 29, 4, 30, 9, 30, 4, 31, 9, 31, 4, 32, 9, 32, 4, 33, 9, 33, 4, 34, 9, 34, 4, 35, 9, 35, 4, 36, 9, 36, 4, 37, 9, 37, 4, 38, 9, 38, 4, 39, 9, 39, 4, 40, 9, 40, 4, 41, 9, 41, 4, 42, 9, 42, 4, 43, 9, 43, 4, 44, 9, 44, 4, 45, 9, 45, 4, 46, 9, 46, 4, 47, 9, 47, 4, 48, 9, 48, 4, 49, 9, 49, 4, 50, 9, 50, 4, 51, 9, 51, 4, 52, 9, 52, 4, 53, 9, 53, 4, 54, 9, 54, 4, 55, 9, 55, 4, 56, 9, 56, 4, 57, 9, 57, 4, 58, 9, 58, 4, 59, 9, 59, 4, 60, 9, 60, 4, 61, 9, 61, 4, 62, 9, 62, 4, 63, 9, 63, 4, 64, 9, 64, 3, 2, 3, 2, 3, 3, 3, 3, 3, 3, 3, 4, 3, 4, 3, 4, 3, 4, 3, 5, 3, 5, 3, 5, 3, 5, 3, 6, 3, 6, 3, 6, 3, 6, 3, 6, 3, 7, 3, 7, 3, 8, 3, 8, 3, 9, 3, 9, 3, 9, 3, 10, 3, 10, 3, 10, 3, 11, 3, 11, 3, 11, 3, 11, 3, 12, 3, 12, 3, 12, 3, 12, 3, 13, 3, 13, 3, 13, 3, 13, 3, 14, 3, 14, 3, 14, 3, 14, 3, 15, 3, 15, 3, 15, 3, 16, 3, 16, 3, 16, 3, 17, 3, 17, 3, 17, 3, 17, 3, 18, 3, 18, 3, 18, 3, 18, 3, 19, 3, 19, 3, 19, 3, 19, 3, 20, 3, 20, 3, 20, 3, 20, 3, 21, 3, 21, 3, 21, 3, 22, 3, 22, 3, 22, 3, 23, 3, 23, 3, 23, 3, 23, 3, 24, 3, 24, 3, 24, 3, 24, 3, 25, 3, 25, 3, 25, 3, 25, 3, 26, 3, 26, 3, 26, 3, 26, 3, 27, 3, 27, 3, 27, 3, 27, 3, 27, 3, 28, 3, 28, 3, 28, 3, 28, 3, 28, 3, 29, 3, 29, 3, 29, 3, 29, 3, 30, 3, 30, 3, 30, 3, 30, 3, 31, 3, 31, 3, 31, 3, 31, 3, 31, 3, 32, 3, 32, 3, 32, 3, 32, 3, 32, 3, 33, 3, 33, 3, 33, 3, 33, 3, 33, 3, 34, 3, 34, 3, 34, 3, 34, 3, 34, 3, 35, 3, 35, 3, 35, 3, 35, 3, 36, 3, 36, 3, 36, 3, 36, 3, 37, 3, 37, 3, 37, 3, 37, 3, 37, 3, 38, 3, 38, 3, 38, 3, 38, 3, 38, 3, 39, 3, 39, 3, 39, 3, 39, 3, 39, 3, 40, 3, 40, 3, 40, 3, 40, 3, 40, 3, 41, 3, 41, 3, 41, 3, 41, 3, 42, 3, 42, 3, 43, 3, 43, 3, 44, 3, 44, 3, 45, 3, 45, 3, 46, 3, 46, 3, 47, 3, 47, 3, 48, 3, 48, 3, 48, 3, 49, 3, 49, 3, 49, 3, 50, 6, 50, 307, 10, 50, 13, 50, 14, 50, 308, 3, 51, 3, 51, 6, 51, 313, 10, 51, 13, 51, 14, 51, 314, 3, 52, 3, 52, 3, 52, 3, 53, 3, 53, 5, 53, 322, 10, 53, 3, 54, 3, 54, 5, 54, 326, 10, 54, 3, 55, 3, 55, 3, 55, 3, 56, 3, 56, 3, 56, 3, 57, 3, 57, 3, 57, 3, 57, 3, 57, 7, 57, 339, 10, 57, 12, 57, 14, 57, 342, 11, 57, 3, 57, 3, 57, 5, 57, 346, 10, 57, 3, 58, 3, 58, 3, 58, 3, 58, 7, 58, 352, 10, 58, 12, 58, 14, 58, 355, 11, 58, 3, 58, 3, 58, 3, 59, 3, 59, 3, 59, 5, 59, 362, 10, 59, 3, 60, 3, 60, 3, 60, 3, 60, 3, 61, 3, 61, 3, 61, 3, 61, 7, 61, 372, 10, 61, 12, 61, 14, 61, 375, 11, 61, 3, 61, 5, 61, 378, 10, 61, 3, 61, 3, 61, 3, 61, 3, 61, 3, 62, 3, 62, 3, 62, 3, 62, 7, 62, 388, 10, 62, 12, 62, 14, 62, 391, 11, 62, 3, 62, 3, 62, 3, 62, 3, 62, 3, 62, 3, 63, 3, 63, 3, 63, 3, 63, 3, 64, 3, 64, 3, 64, 3, 389, 2, 65, 3, 3, 5, 4, 7, 5, 9, 6, 11, 7, 13, 8, 15, 9, 17, 10, 19, 11, 21, 12, 23, 13, 25, 14, 27, 15, 29, 16, 31, 17, 33, 18, 35, 19, 37, 20, 39, 21, 41, 22, 43, 23, 45, 24, 47, 25, 49, 26, 51, 27, 53, 28, 55, 29, 57, 30, 59, 31, 61, 32, 63, 33, 65, 34, 67, 35, 69, 36, 71, 37, 73, 38, 75, 39, 77, 40, 79, 41, 81, 42, 83, 43, 85, 44, 87, 45, 89, 46, 91, 47, 93, 48, 95, 49, 97, 50, 99, 51, 101, 52, 103, 2, 105, 2, 107, 2, 109, 53, 111, 54, 113, 55, 115, 56, 117, 57, 119, 58, 121, 59, 123, 60, 125, 61, 127, 62, 3, 2, 10, 7, 2, 48, 48, 50, 59, 67, 92, 97, 97, 99, 124, 6, 2, 50, 59, 67, 92, 97, 97, 99, 124, 3, 2, 93, 95, 4, 2, 44, 44, 93, 95, 3, 2, 36, 36, 5, 2, 12, 12, 15, 15, 8234, 8235, 4, 2, 12, 12, 15, 15, 5, 2, 11, 12, 15, 15, 34, 34, 2, 412, 2, 3, 3, 2, 2, 2, 2, 5, 3, 2, 2, 2, 2, 7, 3, 2, 2, 2, 2, 9, 3, 2, 2, 2, 2, 11, 3, 2, 2, 2, 2, 13, 3, 2, 2, 2, 2, 15, 3, 2, 2, 2, 2, 17, 3, 2, 2, 2, 2, 19, 3, 2, 2, 2, 2, 21, 3, 2, 2, 2, 2, 23, 3, 2, 2, 2, 2, 25, 3, 2, 2, 2, 2, 27, 3, 2, 2, 2, 2, 29, 3, 2, 2, 2, 2, 31, 3, 2, 2, 2, 2, 33, 3, 2, 2, 2, 2, 35, 3, 2, 2, 2, 2, 37, 3, 2, 2, 2, 2, 39, 3, 2, 2, 2, 2, 41, 3, 2, 2, 2, 2, 43, 3, 2, 2, 2, 2, 45, 3, 2, 2, 2, 2, 47, 3, 2, 2, 2, 2, 49, 3, 2, 2, 2, 2, 51, 3, 2, 2, 2, 2, 53, 3, 2, 2, 2, 2, 55, 3, 2, 2, 2, 2, 57, 3, 2, 2, 2, 2, 59, 3, 2, 2, 2, 2, 61, 3, 2, 2, 2, 2, 63, 3, 2, 2, 2, 2, 65, 3, 2, 2, 2, 2, 67, 3, 2, 2, 2, 2, 69, 3, 2, 2, 2, 2, 71, 3, 2, 2, 2, 2, 73, 3, 2, 2, 2, 2, 75, 3, 2, 2, 2, 2, 77, 3, 2, 2, 2, 2, 79, 3, 2, 2, 2, 2, 81, 3, 2, 2, 2, 2, 83, 3, 2, 2, 2, 2, 85, 3, 2, 2, 2, 2, 87, 3, 2, 2, 2, 2, 89, 3, 2, 2, 2, 2, 91, 3, 2, 2, 2, 2, 93, 3, 2, 2, 2, 2, 95, 3, 2, 2, 2, 2, 97, 3, 2, 2, 2, 2, 99, 3, 2, 2, 2, 2, 101, 3, 2, 2, 2, 2, 109, 3, 2, 2, 2, 2, 111, 3, 2, 2, 2, 2, 113, 3, 2, 2, 2, 2, 115, 3, 2, 2, 2, 2, 117, 3, 2, 2, 2, 2, 119, 3, 2, 2, 2, 2, 121, 3, 2, 2, 2, 2, 123, 3, 2, 2, 2, 2, 125, 3, 2, 2, 2, 2, 127, 3, 2, 2, 2, 3, 129, 3, 2, 2, 2, 5, 131, 3, 2, 2, 2, 7, 134, 3, 2, 2, 2, 9, 138, 3, 2, 2, 2, 11, 142, 3, 2, 2, 2, 13, 147, 3, 2, 2, 2, 15, 149, 3, 2, 2, 2, 17, 151, 3, 2, 2, 2, 19, 154, 3, 2, 2, 2, 21, 157, 3, 2, 2, 2, 23, 161, 3, 2, 2, 2, 25, 165, 3, 2, 2, 2, 27, 169, 3, 2, 2, 2, 29, 173, 3, 2, 2, 2, 31, 176, 3, 2, 2, 2, 33, 179, 3, 2, 2, 2, 35, 183, 3, 2, 2, 2, 37, 187, 3, 2, 2, 2, 39, 191, 3, 2, 2, 2, 41, 195, 3, 2, 2, 2, 43, 198, 3, 2, 2, 2, 45, 201, 3, 2, 2, 2, 47, 205, 3, 2, 2, 2, 49, 209, 3, 2, 2, 2, 51, 213, 3, 2, 2, 2, 53, 217, 3, 2, 2, 2, 55, 222, 3, 2, 2, 2, 57, 227, 3, 2, 2, 2, 59, 231, 3, 2, 2, 2, 61, 235, 3, 2, 2, 2, 63, 240, 3, 2, 2, 2, 65, 245, 3, 2, 2, 2, 67, 250, 3, 2, 2, 2, 69, 255, 3, 2, 2, 2, 71, 259, 3, 2, 2, 2, 73, 263, 3, 2, 2, 2, 75, 268, 3, 2, 2, 2, 77, 273, 3, 2, 2, 2, 79, 278, 3, 2, 2, 2, 81, 283, 3, 2, 2, 2, 83, 287, 3, 2, 2, 2, 85, 289, 3, 2, 2, 2, 87, 291, 3, 2, 2, 2, 89, 293, 3, 2, 2, 2, 91, 295, 3, 2, 2, 2, 93, 297, 3, 2, 2, 2, 95, 299, 3, 2, 2, 2, 97, 302, 3, 2, 2, 2, 99, 306, 3, 2, 2, 2, 101, 310, 3, 2, 2, 2, 103, 316, 3, 2, 2, 2, 105, 321, 3, 2, 2, 2, 107, 325, 3, 2, 2, 2, 109, 327, 3, 2, 2, 2, 111, 330, 3, 2, 2, 2, 113, 345, 3, 2, 2, 2, 115, 347, 3, 2, 2, 2, 117, 361, 3, 2, 2, 2, 119, 363, 3, 2, 2, 2, 121, 367, 3, 2, 2, 2, 123, 383, 3, 2, 2, 2, 125, 397, 3, 2, 2, 2, 127, 401, 3, 2, 2, 2, 129, 130, 7, 97, 2, 2, 130, 4, 3, 2, 2, 2, 131, 132, 7, 62, 2, 2, 132, 133, 7, 64, 2, 2, 133, 6, 3, 2, 2, 2, 134, 135, 7, 62, 2, 2, 135, 136, 7, 63, 2, 2, 136, 137, 7, 64, 2, 2, 137, 8, 3, 2, 2, 2, 138, 139, 7, 97, 2, 2, 139, 140, 7, 62, 2, 2, 140, 141, 7, 64, 2, 2, 141, 10, 3, 2, 2, 2, 142, 143, 7, 97, 2, 2, 143, 144, 7, 62, 2, 2, 144, 145, 7, 63, 2, 2, 145, 146, 7, 64, 2, 2, 146, 12, 3, 2, 2, 2, 147, 148, 7, 64, 2, 2, 148, 14, 3, 2, 2, 2, 149, 150, 7, 62, 2, 2, 150, 16, 3, 2, 2, 2, 151, 152, 7, 63, 2, 2, 152, 153, 7, 64, 2, 2, 153, 18, 3, 2, 2, 2, 154, 155, 7, 62, 2, 2, 155, 156, 7, 63, 2, 2, 156, 20, 3, 2, 2, 2, 157, 158, 7, 97, 2, 2, 158, 159, 7, 63, 2, 2, 159, 160, 7, 64, 2, 2, 160, 22, 3, 2, 2, 2, 161, 162, 7, 97, 2, 2, 162, 163, 7, 62, 2, 2, 163, 164, 7, 63, 2, 2, 164, 24, 3, 2, 2, 2, 165, 166, 7, 48, 2, 2, 166, 167, 7, 48, 2, 2, 167, 168, 7, 64, 2, 2, 168, 26, 3, 2, 2, 2, 169, 170, 7, 62, 2, 2, 170, 171, 7, 48, 2, 2, 171, 172, 7, 48, 2, 2, 172, 28, 3, 2, 2, 2, 173, 174, 7, 47, 2, 2, 174, 175, 7, 64, 2, 2, 175, 30, 3, 2, 2, 2, 176, 177, 7, 62, 2, 2, 177, 178, 7, 47, 2, 2, 178, 32, 3, 2, 2, 2, 179, 180, 7, 47, 2, 2, 180, 181, 7, 126, 2, 2, 181, 182, 7, 64, 2, 2, 182, 34, 3, 2, 2, 2, 183, 184, 7, 62, 2, 2, 184, 185, 7, 126, 2, 2, 185, 186, 7, 47, 2, 2, 186, 36, 3, 2, 2, 2, 187, 188, 7, 47, 2, 2, 188, 189, 7, 49, 2, 2, 189, 190, 7, 64, 2, 2, 190, 38, 3, 2, 2, 2, 191, 192, 7, 62, 2, 2, 192, 193, 7, 49, 2, 2, 193, 194, 7, 47, 2, 2, 194, 40, 3, 2, 2, 2, 195, 196, 7, 128, 2, 2, 196, 197, 7, 64, 2, 2, 197, 42, 3, 2, 2, 2, 198, 199, 7, 62, 2, 2, 199, 200, 7, 128, 2, 2, 200, 44, 3, 2, 2, 2, 201, 202, 7, 128, 2, 2, 202, 203, 7, 126, 2, 2, 203, 204, 7, 64, 2, 2, 204, 46, 3, 2, 2, 2, 205, 206, 7, 62, 2, 2, 206, 207, 7, 126, 2, 2, 207, 208, 7, 128, 2, 2, 208, 48, 3, 2, 2, 2, 209, 210, 7, 128, 2, 2, 210, 211, 7, 49, 2, 2, 211, 212, 7, 64, 2, 2, 212, 50, 3, 2, 2, 2, 213, 214, 7, 62, 2, 2, 214, 215, 7, 49, 2, 2, 215, 216, 7, 128, 2, 2, 216, 52, 3, 2, 2, 2, 217, 218, 7, 97, 2, 2, 218, 219, 7, 48, 2, 2, 219, 220, 7, 48, 2, 2, 220, 221, 7, 64, 2, 2, 221, 54, 3, 2, 2, 2, 222, 223, 7, 97, 2, 2, 223, 224, 7, 62, 2, 2, 224, 225, 7, 48, 2, 2, 225, 226, 7, 48, 2, 2, 226, 56, 3, 2, 2, 2, 227, 228, 7, 97, 2, 2, 228, 229, 7, 47, 2, 2, 229, 230, 7, 64, 2, 2, 230, 58, 3, 2, 2, 2, 231, 232, 7, 97, 2, 2, 232, 233, 7, 62, 2, 2, 233, 234, 7, 47, 2, 2, 234, 60, 3, 2, 2, 2, 235, 236, 7, 97, 2, 2, 236, 237, 7, 47, 2, 2, 237, 238, 7, 126, 2, 2, 238, 239, 7, 64, 2, 2, 239, 62, 3, 2, 2, 2, 240, 241, 7, 97, 2, 2, 241, 242, 7, 62, 2, 2, 242, 243, 7, 126, 2, 2, 243, 244, 7, 47, 2, 2, 244, 64, 3, 2, 2, 2, 245, 246, 7, 97, 2, 2, 246, 247, 7, 47, 2, 2, 247, 248, 7, 49, 2, 2, 248, 249, 7, 64, 2, 2, 249, 66, 3, 2, 2, 2, 250, 251, 7, 97, 2, 2, 251, 252, 7, 62, 2, 2, 252, 253, 7, 49, 2, 2, 253, 254, 7, 47, 2, 2, 254, 68, 3, 2, 2, 2, 255, 256, 7, 97, 2, 2, 256, 257, 7, 128, 2, 2, 257, 258, 7, 64, 2, 2, 258, 70, 3, 2, 2, 2, 259, 260, 7, 97, 2, 2, 260, 261, 7, 62, 2, 2, 261, 262, 7, 128, 2, 2, 262, 72, 3, 2, 2, 2, 263, 264, 7, 97, 2, 2, 264, 265, 7, 128, 2, 2, 265, 266, 7, 126, 2, 2, 266, 267, 7, 64, 2, 2, 267, 74, 3, 2, 2, 2, 268, 269, 7, 97, 2, 2, 269, 270, 7, 62, 2, 2, 270, 271, 7, 126, 2, 2, 271, 272, 7, 128, 2, 2, 272, 76, 3, 2, 2, 2, 273, 274, 7, 97, 2, 2, 274, 275, 7, 128, 2, 2, 275, 276, 7, 49, 2, 2, 276, 277, 7, 64, 2, 2, 277, 78, 3, 2, 2, 2, 278, 279, 7, 97, 2, 2, 279, 280, 7, 62, 2, 2, 280, 281, 7, 49, 2, 2, 281, 282, 7, 128, 2, 2, 282, 80, 3, 2, 2, 2, 283, 284, 7, 48, 2, 2, 284, 285, 7, 48, 2, 2, 285, 286, 7, 48, 2, 2, 286, 82, 3, 2, 2, 2, 287, 288, 7, 63, 2, 2, 288, 84, 3, 2, 2, 2, 289, 290, 7, 42, 2, 2, 290, 86, 3, 2, 2, 2, 291, 292, 7, 43, 2, 2, 292, 88, 3, 2, 2, 2, 293, 294, 7, 61, 2, 2, 294, 90, 3, 2, 2, 2, 295, 296, 7, 125, 2, 2, 296, 92, 3, 2, 2, 2, 297, 298, 7, 127, 2, 2, 298, 94, 3, 2, 2, 2, 299, 300, 7, 42, 2, 2, 300, 301, 7, 44, 2, 2, 301, 96, 3, 2, 2, 2, 302, 303, 7, 44, 2, 2, 303, 304, 7, 43, 2, 2, 304, 98, 3, 2, 2, 2, 305, 307, 9, 2, 2, 2, 306, 305, 3, 2, 2, 2, 307, 308, 3, 2, 2, 2, 308, 306, 3, 2, 2, 2, 308, 309, 3, 2, 2, 2, 309, 100, 3, 2, 2, 2, 310, 312, 7, 66, 2, 2, 311, 313, 9, 3, 2, 2, 312, 311, 3, 2, 2, 2, 313, 314, 3, 2, 2, 2, 314, 312, 3, 2, 2, 2, 314, 315, 3, 2, 2, 2, 315, 102, 3, 2, 2, 2, 316, 317, 7, 94, 2, 2, 317, 318, 4, 93, 95, 2, 318, 104, 3, 2, 2, 2, 319, 322, 5, 103, 52, 2, 320, 322, 10, 4, 2, 2, 321, 319, 3, 2, 2, 2, 321, 320, 3, 2, 2, 2, 322, 106, 3, 2, 2, 2, 323, 326, 5, 103, 52, 2, 324, 326, 10, 5, 2, 2, 325, 323, 3, 2, 2, 2, 325, 324, 3, 2, 2, 2, 326, 108, 3, 2, 2, 2, 327, 328, 7, 93, 2, 2, 328, 329, 7, 44, 2, 2, 329, 110, 3, 2, 2, 2, 330, 331, 7, 44, 2, 2, 331, 332, 7, 95, 2, 2, 332, 112, 3, 2, 2, 2, 333, 334, 7, 93, 2, 2, 334, 346, 7, 95, 2, 2, 335, 336, 7, 93, 2, 2, 336, 340, 5, 107, 54, 2, 337, 339, 5, 105, 53, 2, 338, 337, 3, 2, 2, 2, 339, 342, 3, 2, 2, 2, 340, 338, 3, 2, 2, 2, 340, 341, 3, 2, 2, 2, 341, 343, 3, 2, 2, 2, 342, 340, 3, 2, 2, 2, 343, 344, 7, 95, 2, 2, 344, 346, 3, 2, 2, 2, 345, 333, 3, 2, 2, 2, 345, 335, 3, 2, 2, 2, 346, 114, 3, 2, 2, 2, 347, 353, 7, 36, 2, 2, 348, 352, 10, 6, 2, 2, 349, 350, 7, 94, 2, 2, 350, 352, 7, 36, 2, 2, 351, 348, 3, 2, 2, 2, 351, 349, 3, 2, 2, 2, 352, 355, 3, 2, 2, 2, 353, 351, 3, 2, 2, 2, 353, 354, 3, 2, 2, 2, 354, 356, 3, 2, 2, 2, 355, 353, 3, 2, 2, 2, 356, 357, 7, 36, 2, 2, 357, 116, 3, 2, 2, 2, 358, 362, 7, 60, 2, 2, 359, 360, 7, 60, 2, 2, 360, 362, 7, 60, 2, 2, 361, 358, 3, 2, 2, 2, 361, 359, 3, 2, 2, 2, 362, 118, 3, 2, 2, 2, 363, 364, 9, 7, 2, 2, 364, 365, 3, 2, 2, 2, 365, 366, 8, 60, 2, 2, 366, 120, 3, 2, 2, 2, 367, 368, 7, 49, 2, 2, 368, 369, 7, 49, 2, 2, 369, 373, 3, 2, 2, 2, 370, 372, 10, 8, 2, 2, 371, 370, 3, 2, 2, 2, 372, 375, 3, 2, 2, 2, 373, 371, 3, 2, 2, 2, 373, 374, 3, 2, 2, 2, 374, 377, 3, 2, 2, 2, 375, 373, 3, 2, 2, 2, 376, 378, 7, 15, 2, 2, 377, 376, 3, 2, 2, 2, 377, 378, 3, 2, 2, 2, 378, 379, 3, 2, 2, 2, 379, 380, 7, 12, 2, 2, 380, 381, 3, 2, 2, 2, 381, 382, 8, 61, 2, 2, 382, 122, 3, 2, 2, 2, 383, 384, 7, 49, 2, 2, 384, 385, 7, 44, 2, 2, 385, 389, 3, 2, 2, 2, 386, 388, 11, 2, 2, 2, 387, 386, 3, 2, 2, 2, 388, 391, 3, 2, 2, 2, 389, 390, 3, 2, 2, 2, 389, 387, 3, 2, 2, 2, 390, 392, 3, 2, 2, 2, 391, 389, 3, 2, 2, 2, 392, 393, 7, 44, 2, 2, 393, 394, 7, 49, 2, 2, 394, 395, 3, 2, 2, 2, 395, 396, 8, 62, 2, 2, 396, 124, 3, 2, 2, 2, 397, 398, 9, 9, 2, 2, 398, 399, 3, 2, 2, 2, 399, 400, 8, 63, 2, 2, 400, 126, 3, 2, 2, 2, 401, 402, 7, 61, 2, 2, 402, 403, 7, 61, 2, 2, 403, 128, 3, 2, 2, 2, 15, 2, 308, 314, 321, 325, 340, 345, 351, 353, 361, 373, 377, 389, 3, 2, 3, 2]
\ No newline at end of file
diff --git a/db/sc/scs/antlr/scsLexer.py b/db/sc/scs/antlr/scsLexer.py
new file mode 100644
index 0000000..2fd5abe
--- /dev/null
+++ b/db/sc/scs/antlr/scsLexer.py
@@ -0,0 +1,296 @@
+# Generated from sc/scs/scs.g4 by ANTLR 4.9.2
+from antlr4 import *
+from io import StringIO
+import sys
+if sys.version_info[1] > 5:
+    from typing import TextIO
+else:
+    from typing.io import TextIO
+
+
+
+def serializedATN():
+    with StringIO() as buf:
+        buf.write("\3\u608b\ua72a\u8133\ub9ed\u417c\u3be7\u7786\u5964\2>")
+        buf.write("\u0194\b\1\4\2\t\2\4\3\t\3\4\4\t\4\4\5\t\5\4\6\t\6\4\7")
+        buf.write("\t\7\4\b\t\b\4\t\t\t\4\n\t\n\4\13\t\13\4\f\t\f\4\r\t\r")
+        buf.write("\4\16\t\16\4\17\t\17\4\20\t\20\4\21\t\21\4\22\t\22\4\23")
+        buf.write("\t\23\4\24\t\24\4\25\t\25\4\26\t\26\4\27\t\27\4\30\t\30")
+        buf.write("\4\31\t\31\4\32\t\32\4\33\t\33\4\34\t\34\4\35\t\35\4\36")
+        buf.write("\t\36\4\37\t\37\4 \t \4!\t!\4\"\t\"\4#\t#\4$\t$\4%\t%")
+        buf.write("\4&\t&\4\'\t\'\4(\t(\4)\t)\4*\t*\4+\t+\4,\t,\4-\t-\4.")
+        buf.write("\t.\4/\t/\4\60\t\60\4\61\t\61\4\62\t\62\4\63\t\63\4\64")
+        buf.write("\t\64\4\65\t\65\4\66\t\66\4\67\t\67\48\t8\49\t9\4:\t:")
+        buf.write("\4;\t;\4<\t<\4=\t=\4>\t>\4?\t?\4@\t@\3\2\3\2\3\3\3\3\3")
+        buf.write("\3\3\4\3\4\3\4\3\4\3\5\3\5\3\5\3\5\3\6\3\6\3\6\3\6\3\6")
+        buf.write("\3\7\3\7\3\b\3\b\3\t\3\t\3\t\3\n\3\n\3\n\3\13\3\13\3\13")
+        buf.write("\3\13\3\f\3\f\3\f\3\f\3\r\3\r\3\r\3\r\3\16\3\16\3\16\3")
+        buf.write("\16\3\17\3\17\3\17\3\20\3\20\3\20\3\21\3\21\3\21\3\21")
+        buf.write("\3\22\3\22\3\22\3\22\3\23\3\23\3\23\3\23\3\24\3\24\3\24")
+        buf.write("\3\24\3\25\3\25\3\25\3\26\3\26\3\26\3\27\3\27\3\27\3\27")
+        buf.write("\3\30\3\30\3\30\3\30\3\31\3\31\3\31\3\31\3\32\3\32\3\32")
+        buf.write("\3\32\3\33\3\33\3\33\3\33\3\33\3\34\3\34\3\34\3\34\3\34")
+        buf.write("\3\35\3\35\3\35\3\35\3\36\3\36\3\36\3\36\3\37\3\37\3\37")
+        buf.write("\3\37\3\37\3 \3 \3 \3 \3 \3!\3!\3!\3!\3!\3\"\3\"\3\"\3")
+        buf.write("\"\3\"\3#\3#\3#\3#\3$\3$\3$\3$\3%\3%\3%\3%\3%\3&\3&\3")
+        buf.write("&\3&\3&\3\'\3\'\3\'\3\'\3\'\3(\3(\3(\3(\3(\3)\3)\3)\3")
+        buf.write(")\3*\3*\3+\3+\3,\3,\3-\3-\3.\3.\3/\3/\3\60\3\60\3\60\3")
+        buf.write("\61\3\61\3\61\3\62\6\62\u0133\n\62\r\62\16\62\u0134\3")
+        buf.write("\63\3\63\6\63\u0139\n\63\r\63\16\63\u013a\3\64\3\64\3")
+        buf.write("\64\3\65\3\65\5\65\u0142\n\65\3\66\3\66\5\66\u0146\n\66")
+        buf.write("\3\67\3\67\3\67\38\38\38\39\39\39\39\39\79\u0153\n9\f")
+        buf.write("9\169\u0156\139\39\39\59\u015a\n9\3:\3:\3:\3:\7:\u0160")
+        buf.write("\n:\f:\16:\u0163\13:\3:\3:\3;\3;\3;\5;\u016a\n;\3<\3<")
+        buf.write("\3<\3<\3=\3=\3=\3=\7=\u0174\n=\f=\16=\u0177\13=\3=\5=")
+        buf.write("\u017a\n=\3=\3=\3=\3=\3>\3>\3>\3>\7>\u0184\n>\f>\16>\u0187")
+        buf.write("\13>\3>\3>\3>\3>\3>\3?\3?\3?\3?\3@\3@\3@\3\u0185\2A\3")
+        buf.write("\3\5\4\7\5\t\6\13\7\r\b\17\t\21\n\23\13\25\f\27\r\31\16")
+        buf.write("\33\17\35\20\37\21!\22#\23%\24\'\25)\26+\27-\30/\31\61")
+        buf.write("\32\63\33\65\34\67\359\36;\37= ?!A\"C#E$G%I&K\'M(O)Q*")
+        buf.write("S+U,W-Y.[/]\60_\61a\62c\63e\64g\2i\2k\2m\65o\66q\67s8")
+        buf.write("u9w:y;{<}=\177>\3\2\n\7\2\60\60\62;C\\aac|\6\2\62;C\\")
+        buf.write("aac|\3\2]_\4\2,,]_\3\2$$\5\2\f\f\17\17\u202a\u202b\4\2")
+        buf.write("\f\f\17\17\5\2\13\f\17\17\"\"\2\u019c\2\3\3\2\2\2\2\5")
+        buf.write("\3\2\2\2\2\7\3\2\2\2\2\t\3\2\2\2\2\13\3\2\2\2\2\r\3\2")
+        buf.write("\2\2\2\17\3\2\2\2\2\21\3\2\2\2\2\23\3\2\2\2\2\25\3\2\2")
+        buf.write("\2\2\27\3\2\2\2\2\31\3\2\2\2\2\33\3\2\2\2\2\35\3\2\2\2")
+        buf.write("\2\37\3\2\2\2\2!\3\2\2\2\2#\3\2\2\2\2%\3\2\2\2\2\'\3\2")
+        buf.write("\2\2\2)\3\2\2\2\2+\3\2\2\2\2-\3\2\2\2\2/\3\2\2\2\2\61")
+        buf.write("\3\2\2\2\2\63\3\2\2\2\2\65\3\2\2\2\2\67\3\2\2\2\29\3\2")
+        buf.write("\2\2\2;\3\2\2\2\2=\3\2\2\2\2?\3\2\2\2\2A\3\2\2\2\2C\3")
+        buf.write("\2\2\2\2E\3\2\2\2\2G\3\2\2\2\2I\3\2\2\2\2K\3\2\2\2\2M")
+        buf.write("\3\2\2\2\2O\3\2\2\2\2Q\3\2\2\2\2S\3\2\2\2\2U\3\2\2\2\2")
+        buf.write("W\3\2\2\2\2Y\3\2\2\2\2[\3\2\2\2\2]\3\2\2\2\2_\3\2\2\2")
+        buf.write("\2a\3\2\2\2\2c\3\2\2\2\2e\3\2\2\2\2m\3\2\2\2\2o\3\2\2")
+        buf.write("\2\2q\3\2\2\2\2s\3\2\2\2\2u\3\2\2\2\2w\3\2\2\2\2y\3\2")
+        buf.write("\2\2\2{\3\2\2\2\2}\3\2\2\2\2\177\3\2\2\2\3\u0081\3\2\2")
+        buf.write("\2\5\u0083\3\2\2\2\7\u0086\3\2\2\2\t\u008a\3\2\2\2\13")
+        buf.write("\u008e\3\2\2\2\r\u0093\3\2\2\2\17\u0095\3\2\2\2\21\u0097")
+        buf.write("\3\2\2\2\23\u009a\3\2\2\2\25\u009d\3\2\2\2\27\u00a1\3")
+        buf.write("\2\2\2\31\u00a5\3\2\2\2\33\u00a9\3\2\2\2\35\u00ad\3\2")
+        buf.write("\2\2\37\u00b0\3\2\2\2!\u00b3\3\2\2\2#\u00b7\3\2\2\2%\u00bb")
+        buf.write("\3\2\2\2\'\u00bf\3\2\2\2)\u00c3\3\2\2\2+\u00c6\3\2\2\2")
+        buf.write("-\u00c9\3\2\2\2/\u00cd\3\2\2\2\61\u00d1\3\2\2\2\63\u00d5")
+        buf.write("\3\2\2\2\65\u00d9\3\2\2\2\67\u00de\3\2\2\29\u00e3\3\2")
+        buf.write("\2\2;\u00e7\3\2\2\2=\u00eb\3\2\2\2?\u00f0\3\2\2\2A\u00f5")
+        buf.write("\3\2\2\2C\u00fa\3\2\2\2E\u00ff\3\2\2\2G\u0103\3\2\2\2")
+        buf.write("I\u0107\3\2\2\2K\u010c\3\2\2\2M\u0111\3\2\2\2O\u0116\3")
+        buf.write("\2\2\2Q\u011b\3\2\2\2S\u011f\3\2\2\2U\u0121\3\2\2\2W\u0123")
+        buf.write("\3\2\2\2Y\u0125\3\2\2\2[\u0127\3\2\2\2]\u0129\3\2\2\2")
+        buf.write("_\u012b\3\2\2\2a\u012e\3\2\2\2c\u0132\3\2\2\2e\u0136\3")
+        buf.write("\2\2\2g\u013c\3\2\2\2i\u0141\3\2\2\2k\u0145\3\2\2\2m\u0147")
+        buf.write("\3\2\2\2o\u014a\3\2\2\2q\u0159\3\2\2\2s\u015b\3\2\2\2")
+        buf.write("u\u0169\3\2\2\2w\u016b\3\2\2\2y\u016f\3\2\2\2{\u017f\3")
+        buf.write("\2\2\2}\u018d\3\2\2\2\177\u0191\3\2\2\2\u0081\u0082\7")
+        buf.write("a\2\2\u0082\4\3\2\2\2\u0083\u0084\7>\2\2\u0084\u0085\7")
+        buf.write("@\2\2\u0085\6\3\2\2\2\u0086\u0087\7>\2\2\u0087\u0088\7")
+        buf.write("?\2\2\u0088\u0089\7@\2\2\u0089\b\3\2\2\2\u008a\u008b\7")
+        buf.write("a\2\2\u008b\u008c\7>\2\2\u008c\u008d\7@\2\2\u008d\n\3")
+        buf.write("\2\2\2\u008e\u008f\7a\2\2\u008f\u0090\7>\2\2\u0090\u0091")
+        buf.write("\7?\2\2\u0091\u0092\7@\2\2\u0092\f\3\2\2\2\u0093\u0094")
+        buf.write("\7@\2\2\u0094\16\3\2\2\2\u0095\u0096\7>\2\2\u0096\20\3")
+        buf.write("\2\2\2\u0097\u0098\7?\2\2\u0098\u0099\7@\2\2\u0099\22")
+        buf.write("\3\2\2\2\u009a\u009b\7>\2\2\u009b\u009c\7?\2\2\u009c\24")
+        buf.write("\3\2\2\2\u009d\u009e\7a\2\2\u009e\u009f\7?\2\2\u009f\u00a0")
+        buf.write("\7@\2\2\u00a0\26\3\2\2\2\u00a1\u00a2\7a\2\2\u00a2\u00a3")
+        buf.write("\7>\2\2\u00a3\u00a4\7?\2\2\u00a4\30\3\2\2\2\u00a5\u00a6")
+        buf.write("\7\60\2\2\u00a6\u00a7\7\60\2\2\u00a7\u00a8\7@\2\2\u00a8")
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+        buf.write("\u00ac\7\60\2\2\u00ac\34\3\2\2\2\u00ad\u00ae\7/\2\2\u00ae")
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+        buf.write("\7\u0080\2\2\u011aP\3\2\2\2\u011b\u011c\7\60\2\2\u011c")
+        buf.write("\u011d\7\60\2\2\u011d\u011e\7\60\2\2\u011eR\3\2\2\2\u011f")
+        buf.write("\u0120\7?\2\2\u0120T\3\2\2\2\u0121\u0122\7*\2\2\u0122")
+        buf.write("V\3\2\2\2\u0123\u0124\7+\2\2\u0124X\3\2\2\2\u0125\u0126")
+        buf.write("\7=\2\2\u0126Z\3\2\2\2\u0127\u0128\7}\2\2\u0128\\\3\2")
+        buf.write("\2\2\u0129\u012a\7\177\2\2\u012a^\3\2\2\2\u012b\u012c")
+        buf.write("\7*\2\2\u012c\u012d\7,\2\2\u012d`\3\2\2\2\u012e\u012f")
+        buf.write("\7,\2\2\u012f\u0130\7+\2\2\u0130b\3\2\2\2\u0131\u0133")
+        buf.write("\t\2\2\2\u0132\u0131\3\2\2\2\u0133\u0134\3\2\2\2\u0134")
+        buf.write("\u0132\3\2\2\2\u0134\u0135\3\2\2\2\u0135d\3\2\2\2\u0136")
+        buf.write("\u0138\7B\2\2\u0137\u0139\t\3\2\2\u0138\u0137\3\2\2\2")
+        buf.write("\u0139\u013a\3\2\2\2\u013a\u0138\3\2\2\2\u013a\u013b\3")
+        buf.write("\2\2\2\u013bf\3\2\2\2\u013c\u013d\7^\2\2\u013d\u013e\4")
+        buf.write("]_\2\u013eh\3\2\2\2\u013f\u0142\5g\64\2\u0140\u0142\n")
+        buf.write("\4\2\2\u0141\u013f\3\2\2\2\u0141\u0140\3\2\2\2\u0142j")
+        buf.write("\3\2\2\2\u0143\u0146\5g\64\2\u0144\u0146\n\5\2\2\u0145")
+        buf.write("\u0143\3\2\2\2\u0145\u0144\3\2\2\2\u0146l\3\2\2\2\u0147")
+        buf.write("\u0148\7]\2\2\u0148\u0149\7,\2\2\u0149n\3\2\2\2\u014a")
+        buf.write("\u014b\7,\2\2\u014b\u014c\7_\2\2\u014cp\3\2\2\2\u014d")
+        buf.write("\u014e\7]\2\2\u014e\u015a\7_\2\2\u014f\u0150\7]\2\2\u0150")
+        buf.write("\u0154\5k\66\2\u0151\u0153\5i\65\2\u0152\u0151\3\2\2\2")
+        buf.write("\u0153\u0156\3\2\2\2\u0154\u0152\3\2\2\2\u0154\u0155\3")
+        buf.write("\2\2\2\u0155\u0157\3\2\2\2\u0156\u0154\3\2\2\2\u0157\u0158")
+        buf.write("\7_\2\2\u0158\u015a\3\2\2\2\u0159\u014d\3\2\2\2\u0159")
+        buf.write("\u014f\3\2\2\2\u015ar\3\2\2\2\u015b\u0161\7$\2\2\u015c")
+        buf.write("\u0160\n\6\2\2\u015d\u015e\7^\2\2\u015e\u0160\7$\2\2\u015f")
+        buf.write("\u015c\3\2\2\2\u015f\u015d\3\2\2\2\u0160\u0163\3\2\2\2")
+        buf.write("\u0161\u015f\3\2\2\2\u0161\u0162\3\2\2\2\u0162\u0164\3")
+        buf.write("\2\2\2\u0163\u0161\3\2\2\2\u0164\u0165\7$\2\2\u0165t\3")
+        buf.write("\2\2\2\u0166\u016a\7<\2\2\u0167\u0168\7<\2\2\u0168\u016a")
+        buf.write("\7<\2\2\u0169\u0166\3\2\2\2\u0169\u0167\3\2\2\2\u016a")
+        buf.write("v\3\2\2\2\u016b\u016c\t\7\2\2\u016c\u016d\3\2\2\2\u016d")
+        buf.write("\u016e\b<\2\2\u016ex\3\2\2\2\u016f\u0170\7\61\2\2\u0170")
+        buf.write("\u0171\7\61\2\2\u0171\u0175\3\2\2\2\u0172\u0174\n\b\2")
+        buf.write("\2\u0173\u0172\3\2\2\2\u0174\u0177\3\2\2\2\u0175\u0173")
+        buf.write("\3\2\2\2\u0175\u0176\3\2\2\2\u0176\u0179\3\2\2\2\u0177")
+        buf.write("\u0175\3\2\2\2\u0178\u017a\7\17\2\2\u0179\u0178\3\2\2")
+        buf.write("\2\u0179\u017a\3\2\2\2\u017a\u017b\3\2\2\2\u017b\u017c")
+        buf.write("\7\f\2\2\u017c\u017d\3\2\2\2\u017d\u017e\b=\2\2\u017e")
+        buf.write("z\3\2\2\2\u017f\u0180\7\61\2\2\u0180\u0181\7,\2\2\u0181")
+        buf.write("\u0185\3\2\2\2\u0182\u0184\13\2\2\2\u0183\u0182\3\2\2")
+        buf.write("\2\u0184\u0187\3\2\2\2\u0185\u0186\3\2\2\2\u0185\u0183")
+        buf.write("\3\2\2\2\u0186\u0188\3\2\2\2\u0187\u0185\3\2\2\2\u0188")
+        buf.write("\u0189\7,\2\2\u0189\u018a\7\61\2\2\u018a\u018b\3\2\2\2")
+        buf.write("\u018b\u018c\b>\2\2\u018c|\3\2\2\2\u018d\u018e\t\t\2\2")
+        buf.write("\u018e\u018f\3\2\2\2\u018f\u0190\b?\2\2\u0190~\3\2\2\2")
+        buf.write("\u0191\u0192\7=\2\2\u0192\u0193\7=\2\2\u0193\u0080\3\2")
+        buf.write("\2\2\17\2\u0134\u013a\u0141\u0145\u0154\u0159\u015f\u0161")
+        buf.write("\u0169\u0175\u0179\u0185\3\2\3\2")
+        return buf.getvalue()
+
+
+class scsLexer(Lexer):
+
+    atn = ATNDeserializer().deserialize(serializedATN())
+
+    decisionsToDFA = [ DFA(ds, i) for i, ds in enumerate(atn.decisionToState) ]
+
+    T__0 = 1
+    T__1 = 2
+    T__2 = 3
+    T__3 = 4
+    T__4 = 5
+    T__5 = 6
+    T__6 = 7
+    T__7 = 8
+    T__8 = 9
+    T__9 = 10
+    T__10 = 11
+    T__11 = 12
+    T__12 = 13
+    T__13 = 14
+    T__14 = 15
+    T__15 = 16
+    T__16 = 17
+    T__17 = 18
+    T__18 = 19
+    T__19 = 20
+    T__20 = 21
+    T__21 = 22
+    T__22 = 23
+    T__23 = 24
+    T__24 = 25
+    T__25 = 26
+    T__26 = 27
+    T__27 = 28
+    T__28 = 29
+    T__29 = 30
+    T__30 = 31
+    T__31 = 32
+    T__32 = 33
+    T__33 = 34
+    T__34 = 35
+    T__35 = 36
+    T__36 = 37
+    T__37 = 38
+    T__38 = 39
+    T__39 = 40
+    T__40 = 41
+    T__41 = 42
+    T__42 = 43
+    T__43 = 44
+    T__44 = 45
+    T__45 = 46
+    T__46 = 47
+    T__47 = 48
+    ID_SYSTEM = 49
+    ALIAS_SYMBOLS = 50
+    CONTOUR_BEGIN = 51
+    CONTOUR_END = 52
+    CONTENT_BODY = 53
+    LINK = 54
+    EDGE_ATTR = 55
+    LINE_TERMINATOR = 56
+    LINE_COMMENT = 57
+    MULTINE_COMMENT = 58
+    WS = 59
+    SENTENCE_SEP = 60
+
+    channelNames = [ u"DEFAULT_TOKEN_CHANNEL", u"HIDDEN" ]
+
+    modeNames = [ "DEFAULT_MODE" ]
+
+    literalNames = [ "<INVALID>",
+            "'_'", "'<>'", "'<=>'", "'_<>'", "'_<=>'", "'>'", "'<'", "'=>'", 
+            "'<='", "'_=>'", "'_<='", "'..>'", "'<..'", "'->'", "'<-'", 
+            "'-|>'", "'<|-'", "'-/>'", "'</-'", "'~>'", "'<~'", "'~|>'", 
+            "'<|~'", "'~/>'", "'</~'", "'_..>'", "'_<..'", "'_->'", "'_<-'", 
+            "'_-|>'", "'_<|-'", "'_-/>'", "'_</-'", "'_~>'", "'_<~'", "'_~|>'", 
+            "'_<|~'", "'_~/>'", "'_</~'", "'...'", "'='", "'('", "')'", 
+            "';'", "'{'", "'}'", "'(*'", "'*)'", "'[*'", "'*]'", "';;'" ]
+
+    symbolicNames = [ "<INVALID>",
+            "ID_SYSTEM", "ALIAS_SYMBOLS", "CONTOUR_BEGIN", "CONTOUR_END", 
+            "CONTENT_BODY", "LINK", "EDGE_ATTR", "LINE_TERMINATOR", "LINE_COMMENT", 
+            "MULTINE_COMMENT", "WS", "SENTENCE_SEP" ]
+
+    ruleNames = [ "T__0", "T__1", "T__2", "T__3", "T__4", "T__5", "T__6", 
+                  "T__7", "T__8", "T__9", "T__10", "T__11", "T__12", "T__13", 
+                  "T__14", "T__15", "T__16", "T__17", "T__18", "T__19", 
+                  "T__20", "T__21", "T__22", "T__23", "T__24", "T__25", 
+                  "T__26", "T__27", "T__28", "T__29", "T__30", "T__31", 
+                  "T__32", "T__33", "T__34", "T__35", "T__36", "T__37", 
+                  "T__38", "T__39", "T__40", "T__41", "T__42", "T__43", 
+                  "T__44", "T__45", "T__46", "T__47", "ID_SYSTEM", "ALIAS_SYMBOLS", 
+                  "CONTENT_ESCAPED", "CONTENT_SYBMOL", "CONTENT_SYBMOL_FIRST_END", 
+                  "CONTOUR_BEGIN", "CONTOUR_END", "CONTENT_BODY", "LINK", 
+                  "EDGE_ATTR", "LINE_TERMINATOR", "LINE_COMMENT", "MULTINE_COMMENT", 
+                  "WS", "SENTENCE_SEP" ]
+
+    grammarFileName = "scs.g4"
+
+    def __init__(self, input=None, output:TextIO = sys.stdout):
+        super().__init__(input, output)
+        self.checkVersion("4.9.2")
+        self._interp = LexerATNSimulator(self, self.atn, self.decisionsToDFA, PredictionContextCache())
+        self._actions = None
+        self._predicates = None
+
+
diff --git a/db/sc/scs/antlr/scsLexer.tokens b/db/sc/scs/antlr/scsLexer.tokens
new file mode 100644
index 0000000..6aebcb7
--- /dev/null
+++ b/db/sc/scs/antlr/scsLexer.tokens
@@ -0,0 +1,111 @@
+T__0=1
+T__1=2
+T__2=3
+T__3=4
+T__4=5
+T__5=6
+T__6=7
+T__7=8
+T__8=9
+T__9=10
+T__10=11
+T__11=12
+T__12=13
+T__13=14
+T__14=15
+T__15=16
+T__16=17
+T__17=18
+T__18=19
+T__19=20
+T__20=21
+T__21=22
+T__22=23
+T__23=24
+T__24=25
+T__25=26
+T__26=27
+T__27=28
+T__28=29
+T__29=30
+T__30=31
+T__31=32
+T__32=33
+T__33=34
+T__34=35
+T__35=36
+T__36=37
+T__37=38
+T__38=39
+T__39=40
+T__40=41
+T__41=42
+T__42=43
+T__43=44
+T__44=45
+T__45=46
+T__46=47
+T__47=48
+ID_SYSTEM=49
+ALIAS_SYMBOLS=50
+CONTOUR_BEGIN=51
+CONTOUR_END=52
+CONTENT_BODY=53
+LINK=54
+EDGE_ATTR=55
+LINE_TERMINATOR=56
+LINE_COMMENT=57
+MULTINE_COMMENT=58
+WS=59
+SENTENCE_SEP=60
+'_'=1
+'<>'=2
+'<=>'=3
+'_<>'=4
+'_<=>'=5
+'>'=6
+'<'=7
+'=>'=8
+'<='=9
+'_=>'=10
+'_<='=11
+'..>'=12
+'<..'=13
+'->'=14
+'<-'=15
+'-|>'=16
+'<|-'=17
+'-/>'=18
+'</-'=19
+'~>'=20
+'<~'=21
+'~|>'=22
+'<|~'=23
+'~/>'=24
+'</~'=25
+'_..>'=26
+'_<..'=27
+'_->'=28
+'_<-'=29
+'_-|>'=30
+'_<|-'=31
+'_-/>'=32
+'_</-'=33
+'_~>'=34
+'_<~'=35
+'_~|>'=36
+'_<|~'=37
+'_~/>'=38
+'_</~'=39
+'...'=40
+'='=41
+'('=42
+')'=43
+';'=44
+'{'=45
+'}'=46
+'(*'=47
+'*)'=48
+'[*'=51
+'*]'=52
+';;'=60
diff --git a/db/sc/scs/antlr/scsParser.py b/db/sc/scs/antlr/scsParser.py
new file mode 100644
index 0000000..ecf11cf
--- /dev/null
+++ b/db/sc/scs/antlr/scsParser.py
@@ -0,0 +1,1639 @@
+# Generated from sc/scs/scs.g4 by ANTLR 4.9.2
+# encoding: utf-8
+from antlr4 import *
+from io import StringIO
+import sys
+if sys.version_info[1] > 5:
+	from typing import TextIO
+else:
+	from typing.io import TextIO
+
+
+from sc.scs.types import *
+from enum import Enum
+
+def create_token_context(ctx: any) -> TokenContext:
+	return TokenContext(line=ctx.line, column=ctx.column, text=ctx.text)
+
+class ConnectorType:
+	ARC = 0
+	EDGE = 1
+
+
+def serializedATN():
+    with StringIO() as buf:
+        buf.write("\3\u608b\ua72a\u8133\ub9ed\u417c\u3be7\u7786\u5964\3>")
+        buf.write("\u00e2\4\2\t\2\4\3\t\3\4\4\t\4\4\5\t\5\4\6\t\6\4\7\t\7")
+        buf.write("\4\b\t\b\4\t\t\t\4\n\t\n\4\13\t\13\4\f\t\f\4\r\t\r\4\16")
+        buf.write("\t\16\4\17\t\17\4\20\t\20\4\21\t\21\4\22\t\22\4\23\t\23")
+        buf.write("\4\24\t\24\4\25\t\25\4\26\t\26\4\27\t\27\4\30\t\30\4\31")
+        buf.write("\t\31\3\2\5\2\64\n\2\3\2\3\2\3\2\3\3\3\3\3\3\3\3\7\3=")
+        buf.write("\n\3\f\3\16\3@\13\3\3\3\3\3\3\3\3\4\3\4\3\4\3\5\3\5\3")
+        buf.write("\5\3\6\3\6\3\6\3\6\3\6\3\6\5\6Q\n\6\3\7\7\7T\n\7\f\7\16")
+        buf.write("\7W\13\7\3\7\3\7\3\b\3\b\3\b\3\t\3\t\5\t`\n\t\3\n\3\n")
+        buf.write("\3\n\3\13\3\13\3\13\3\f\3\f\3\f\3\f\3\f\3\r\3\r\3\r\3")
+        buf.write("\r\5\rq\n\r\3\r\3\r\3\r\3\r\3\16\5\16x\n\16\3\16\3\16")
+        buf.write("\3\16\3\17\3\17\3\17\7\17\u0080\n\17\f\17\16\17\u0083")
+        buf.write("\13\17\3\20\3\20\3\20\3\20\3\20\3\21\3\21\3\21\3\21\3")
+        buf.write("\21\3\21\5\21\u0090\n\21\3\22\3\22\3\22\3\23\3\23\3\23")
+        buf.write("\3\23\3\23\3\23\3\23\3\23\3\23\3\23\3\23\3\23\3\23\3\23")
+        buf.write("\3\23\3\23\3\23\3\23\5\23\u00a7\n\23\3\24\3\24\3\24\5")
+        buf.write("\24\u00ac\n\24\3\24\3\24\3\24\3\24\5\24\u00b2\n\24\7\24")
+        buf.write("\u00b4\n\24\f\24\16\24\u00b7\13\24\3\25\3\25\5\25\u00bb")
+        buf.write("\n\25\3\25\3\25\3\25\3\26\3\26\3\26\3\26\6\26\u00c4\n")
+        buf.write("\26\r\26\16\26\u00c5\3\26\3\26\3\27\3\27\5\27\u00cc\n")
+        buf.write("\27\3\27\3\27\3\27\3\27\3\30\3\30\3\30\3\30\7\30\u00d6")
+        buf.write("\n\30\f\30\16\30\u00d9\13\30\3\31\3\31\3\31\6\31\u00de")
+        buf.write("\n\31\r\31\16\31\u00df\3\31\2\2\32\2\4\6\b\n\f\16\20\22")
+        buf.write("\24\26\30\32\34\36 \"$&(*,.\60\2\5\3\2\4\r\3\2\16)\4\2")
+        buf.write("**\63\63\2\u00df\2\63\3\2\2\2\48\3\2\2\2\6D\3\2\2\2\b")
+        buf.write("G\3\2\2\2\nP\3\2\2\2\fU\3\2\2\2\16Z\3\2\2\2\20_\3\2\2")
+        buf.write("\2\22a\3\2\2\2\24d\3\2\2\2\26g\3\2\2\2\30l\3\2\2\2\32")
+        buf.write("w\3\2\2\2\34|\3\2\2\2\36\u0084\3\2\2\2 \u008f\3\2\2\2")
+        buf.write("\"\u0091\3\2\2\2$\u00a6\3\2\2\2&\u00a8\3\2\2\2(\u00b8")
+        buf.write("\3\2\2\2*\u00bf\3\2\2\2,\u00c9\3\2\2\2.\u00d1\3\2\2\2")
+        buf.write("\60\u00dd\3\2\2\2\62\64\7\3\2\2\63\62\3\2\2\2\63\64\3")
+        buf.write("\2\2\2\64\65\3\2\2\2\65\66\7\67\2\2\66\67\b\2\1\2\67\3")
+        buf.write("\3\2\2\289\7\65\2\29:\6\3\2\2:>\b\3\1\2;=\5\16\b\2<;\3")
+        buf.write("\2\2\2=@\3\2\2\2><\3\2\2\2>?\3\2\2\2?A\3\2\2\2@>\3\2\2")
+        buf.write("\2AB\7\66\2\2BC\b\3\1\2C\5\3\2\2\2DE\t\2\2\2EF\b\4\1\2")
+        buf.write("F\7\3\2\2\2GH\t\3\2\2HI\b\5\1\2I\t\3\2\2\2JK\5\6\4\2K")
+        buf.write("L\b\6\1\2LQ\3\2\2\2MN\5\b\5\2NO\b\6\1\2OQ\3\2\2\2PJ\3")
+        buf.write("\2\2\2PM\3\2\2\2Q\13\3\2\2\2RT\5\16\b\2SR\3\2\2\2TW\3")
+        buf.write("\2\2\2US\3\2\2\2UV\3\2\2\2VX\3\2\2\2WU\3\2\2\2XY\7\2\2")
+        buf.write("\3Y\r\3\2\2\2Z[\5\20\t\2[\\\7>\2\2\\\17\3\2\2\2]`\5\26")
+        buf.write("\f\2^`\5.\30\2_]\3\2\2\2_^\3\2\2\2`\21\3\2\2\2ab\7\64")
+        buf.write("\2\2bc\b\n\1\2c\23\3\2\2\2de\t\4\2\2ef\b\13\1\2f\25\3")
+        buf.write("\2\2\2gh\7\64\2\2hi\7+\2\2ij\5$\23\2jk\b\f\1\2k\27\3\2")
+        buf.write("\2\2lm\7,\2\2mn\5 \21\2np\5\n\6\2oq\5\60\31\2po\3\2\2")
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+        buf.write("\3\2\2\2vx\5\60\31\2wv\3\2\2\2wx\3\2\2\2xy\3\2\2\2yz\5")
+        buf.write("$\23\2z{\b\16\1\2{\33\3\2\2\2|\u0081\5\32\16\2}~\7.\2")
+        buf.write("\2~\u0080\5\32\16\2\177}\3\2\2\2\u0080\u0083\3\2\2\2\u0081")
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+        buf.write("\u0081\3\2\2\2\u0084\u0085\7/\2\2\u0085\u0086\b\20\1\2")
+        buf.write("\u0086\u0087\5\34\17\2\u0087\u0088\7\60\2\2\u0088\37\3")
+        buf.write("\2\2\2\u0089\u008a\5\22\n\2\u008a\u008b\b\21\1\2\u008b")
+        buf.write("\u0090\3\2\2\2\u008c\u008d\5\24\13\2\u008d\u008e\b\21")
+        buf.write("\1\2\u008e\u0090\3\2\2\2\u008f\u0089\3\2\2\2\u008f\u008c")
+        buf.write("\3\2\2\2\u0090!\3\2\2\2\u0091\u0092\78\2\2\u0092\u0093")
+        buf.write("\b\22\1\2\u0093#\3\2\2\2\u0094\u0095\5 \21\2\u0095\u0096")
+        buf.write("\b\23\1\2\u0096\u00a7\3\2\2\2\u0097\u0098\5\30\r\2\u0098")
+        buf.write("\u0099\b\23\1\2\u0099\u00a7\3\2\2\2\u009a\u009b\5\36\20")
+        buf.write("\2\u009b\u009c\b\23\1\2\u009c\u00a7\3\2\2\2\u009d\u009e")
+        buf.write("\5\4\3\2\u009e\u009f\b\23\1\2\u009f\u00a7\3\2\2\2\u00a0")
+        buf.write("\u00a1\5\2\2\2\u00a1\u00a2\b\23\1\2\u00a2\u00a7\3\2\2")
+        buf.write("\2\u00a3\u00a4\5\"\22\2\u00a4\u00a5\b\23\1\2\u00a5\u00a7")
+        buf.write("\3\2\2\2\u00a6\u0094\3\2\2\2\u00a6\u0097\3\2\2\2\u00a6")
+        buf.write("\u009a\3\2\2\2\u00a6\u009d\3\2\2\2\u00a6\u00a0\3\2\2\2")
+        buf.write("\u00a6\u00a3\3\2\2\2\u00a7%\3\2\2\2\u00a8\u00a9\5$\23")
+        buf.write("\2\u00a9\u00ab\b\24\1\2\u00aa\u00ac\5*\26\2\u00ab\u00aa")
+        buf.write("\3\2\2\2\u00ab\u00ac\3\2\2\2\u00ac\u00b5\3\2\2\2\u00ad")
+        buf.write("\u00ae\7.\2\2\u00ae\u00af\5$\23\2\u00af\u00b1\b\24\1\2")
+        buf.write("\u00b0\u00b2\5*\26\2\u00b1\u00b0\3\2\2\2\u00b1\u00b2\3")
+        buf.write("\2\2\2\u00b2\u00b4\3\2\2\2\u00b3\u00ad\3\2\2\2\u00b4\u00b7")
+        buf.write("\3\2\2\2\u00b5\u00b3\3\2\2\2\u00b5\u00b6\3\2\2\2\u00b6")
+        buf.write("\'\3\2\2\2\u00b7\u00b5\3\2\2\2\u00b8\u00ba\5\n\6\2\u00b9")
+        buf.write("\u00bb\5\60\31\2\u00ba\u00b9\3\2\2\2\u00ba\u00bb\3\2\2")
+        buf.write("\2\u00bb\u00bc\3\2\2\2\u00bc\u00bd\5&\24\2\u00bd\u00be")
+        buf.write("\b\25\1\2\u00be)\3\2\2\2\u00bf\u00c3\7\61\2\2\u00c0\u00c1")
+        buf.write("\5(\25\2\u00c1\u00c2\7>\2\2\u00c2\u00c4\3\2\2\2\u00c3")
+        buf.write("\u00c0\3\2\2\2\u00c4\u00c5\3\2\2\2\u00c5\u00c3\3\2\2\2")
+        buf.write("\u00c5\u00c6\3\2\2\2\u00c6\u00c7\3\2\2\2\u00c7\u00c8\7")
+        buf.write("\62\2\2\u00c8+\3\2\2\2\u00c9\u00cb\5\n\6\2\u00ca\u00cc")
+        buf.write("\5\60\31\2\u00cb\u00ca\3\2\2\2\u00cb\u00cc\3\2\2\2\u00cc")
+        buf.write("\u00cd\3\2\2\2\u00cd\u00ce\5&\24\2\u00ce\u00cf\3\2\2\2")
+        buf.write("\u00cf\u00d0\b\27\1\2\u00d0-\3\2\2\2\u00d1\u00d2\5$\23")
+        buf.write("\2\u00d2\u00d7\5,\27\2\u00d3\u00d4\7.\2\2\u00d4\u00d6")
+        buf.write("\5,\27\2\u00d5\u00d3\3\2\2\2\u00d6\u00d9\3\2\2\2\u00d7")
+        buf.write("\u00d5\3\2\2\2\u00d7\u00d8\3\2\2\2\u00d8/\3\2\2\2\u00d9")
+        buf.write("\u00d7\3\2\2\2\u00da\u00db\7\63\2\2\u00db\u00dc\79\2\2")
+        buf.write("\u00dc\u00de\b\31\1\2\u00dd\u00da\3\2\2\2\u00de\u00df")
+        buf.write("\3\2\2\2\u00df\u00dd\3\2\2\2\u00df\u00e0\3\2\2\2\u00e0")
+        buf.write("\61\3\2\2\2\24\63>PU_pw\u0081\u008f\u00a6\u00ab\u00b1")
+        buf.write("\u00b5\u00ba\u00c5\u00cb\u00d7\u00df")
+        return buf.getvalue()
+
+
+class scsParser ( Parser ):
+
+    grammarFileName = "scs.g4"
+
+    atn = ATNDeserializer().deserialize(serializedATN())
+
+    decisionsToDFA = [ DFA(ds, i) for i, ds in enumerate(atn.decisionToState) ]
+
+    sharedContextCache = PredictionContextCache()
+
+    literalNames = [ "<INVALID>", "'_'", "'<>'", "'<=>'", "'_<>'", "'_<=>'", 
+                     "'>'", "'<'", "'=>'", "'<='", "'_=>'", "'_<='", "'..>'", 
+                     "'<..'", "'->'", "'<-'", "'-|>'", "'<|-'", "'-/>'", 
+                     "'</-'", "'~>'", "'<~'", "'~|>'", "'<|~'", "'~/>'", 
+                     "'</~'", "'_..>'", "'_<..'", "'_->'", "'_<-'", "'_-|>'", 
+                     "'_<|-'", "'_-/>'", "'_</-'", "'_~>'", "'_<~'", "'_~|>'", 
+                     "'_<|~'", "'_~/>'", "'_</~'", "'...'", "'='", "'('", 
+                     "')'", "';'", "'{'", "'}'", "'(*'", "'*)'", "<INVALID>", 
+                     "<INVALID>", "'[*'", "'*]'", "<INVALID>", "<INVALID>", 
+                     "<INVALID>", "<INVALID>", "<INVALID>", "<INVALID>", 
+                     "<INVALID>", "';;'" ]
+
+    symbolicNames = [ "<INVALID>", "<INVALID>", "<INVALID>", "<INVALID>", 
+                      "<INVALID>", "<INVALID>", "<INVALID>", "<INVALID>", 
+                      "<INVALID>", "<INVALID>", "<INVALID>", "<INVALID>", 
+                      "<INVALID>", "<INVALID>", "<INVALID>", "<INVALID>", 
+                      "<INVALID>", "<INVALID>", "<INVALID>", "<INVALID>", 
+                      "<INVALID>", "<INVALID>", "<INVALID>", "<INVALID>", 
+                      "<INVALID>", "<INVALID>", "<INVALID>", "<INVALID>", 
+                      "<INVALID>", "<INVALID>", "<INVALID>", "<INVALID>", 
+                      "<INVALID>", "<INVALID>", "<INVALID>", "<INVALID>", 
+                      "<INVALID>", "<INVALID>", "<INVALID>", "<INVALID>", 
+                      "<INVALID>", "<INVALID>", "<INVALID>", "<INVALID>", 
+                      "<INVALID>", "<INVALID>", "<INVALID>", "<INVALID>", 
+                      "<INVALID>", "ID_SYSTEM", "ALIAS_SYMBOLS", "CONTOUR_BEGIN", 
+                      "CONTOUR_END", "CONTENT_BODY", "LINK", "EDGE_ATTR", 
+                      "LINE_TERMINATOR", "LINE_COMMENT", "MULTINE_COMMENT", 
+                      "WS", "SENTENCE_SEP" ]
+
+    RULE_content = 0
+    RULE_contour = 1
+    RULE_connector_edge = 2
+    RULE_connector_arc = 3
+    RULE_connector = 4
+    RULE_syntax = 5
+    RULE_sentence_wrap = 6
+    RULE_sentence = 7
+    RULE_ifdf_alias = 8
+    RULE_idtf_system = 9
+    RULE_sentence_assign = 10
+    RULE_idtf_edge = 11
+    RULE_idtf_set_item = 12
+    RULE_idtf_set_item_list = 13
+    RULE_idtf_set = 14
+    RULE_idtf_atomic = 15
+    RULE_idtf_url = 16
+    RULE_idtf_common = 17
+    RULE_idtf_list = 18
+    RULE_internal_sentence = 19
+    RULE_internal_sentence_list = 20
+    RULE_sentence_lvl_4_list_item = 21
+    RULE_sentence_lvl_common = 22
+    RULE_attr_list = 23
+
+    ruleNames =  [ "content", "contour", "connector_edge", "connector_arc", 
+                   "connector", "syntax", "sentence_wrap", "sentence", "ifdf_alias", 
+                   "idtf_system", "sentence_assign", "idtf_edge", "idtf_set_item", 
+                   "idtf_set_item_list", "idtf_set", "idtf_atomic", "idtf_url", 
+                   "idtf_common", "idtf_list", "internal_sentence", "internal_sentence_list", 
+                   "sentence_lvl_4_list_item", "sentence_lvl_common", "attr_list" ]
+
+    EOF = Token.EOF
+    T__0=1
+    T__1=2
+    T__2=3
+    T__3=4
+    T__4=5
+    T__5=6
+    T__6=7
+    T__7=8
+    T__8=9
+    T__9=10
+    T__10=11
+    T__11=12
+    T__12=13
+    T__13=14
+    T__14=15
+    T__15=16
+    T__16=17
+    T__17=18
+    T__18=19
+    T__19=20
+    T__20=21
+    T__21=22
+    T__22=23
+    T__23=24
+    T__24=25
+    T__25=26
+    T__26=27
+    T__27=28
+    T__28=29
+    T__29=30
+    T__30=31
+    T__31=32
+    T__32=33
+    T__33=34
+    T__34=35
+    T__35=36
+    T__36=37
+    T__37=38
+    T__38=39
+    T__39=40
+    T__40=41
+    T__41=42
+    T__42=43
+    T__43=44
+    T__44=45
+    T__45=46
+    T__46=47
+    T__47=48
+    ID_SYSTEM=49
+    ALIAS_SYMBOLS=50
+    CONTOUR_BEGIN=51
+    CONTOUR_END=52
+    CONTENT_BODY=53
+    LINK=54
+    EDGE_ATTR=55
+    LINE_TERMINATOR=56
+    LINE_COMMENT=57
+    MULTINE_COMMENT=58
+    WS=59
+    SENTENCE_SEP=60
+
+    def __init__(self, input:TokenStream, output:TextIO = sys.stdout):
+        super().__init__(input, output)
+        self.checkVersion("4.9.2")
+        self._interp = ParserATNSimulator(self, self.atn, self.decisionsToDFA, self.sharedContextCache)
+        self._predicates = None
+
+
+
+
+    class ContentContext(ParserRuleContext):
+        __slots__ = 'parser'
+
+        def __init__(self, parser, parent:ParserRuleContext=None, invokingState:int=-1):
+            super().__init__(parent, invokingState)
+            self.parser = parser
+            self.el = None
+            self.v = None # Token
+            self._CONTENT_BODY = None # Token
+
+        def CONTENT_BODY(self):
+            return self.getToken(scsParser.CONTENT_BODY, 0)
+
+        def getRuleIndex(self):
+            return scsParser.RULE_content
+
+
+
+
+    def content(self):
+
+        localctx = scsParser.ContentContext(self, self._ctx, self.state)
+        self.enterRule(localctx, 0, self.RULE_content)
+        self._la = 0 # Token type
+        try:
+            self.enterOuterAlt(localctx, 1)
+            self.state = 49
+            self._errHandler.sync(self)
+            _la = self._input.LA(1)
+            if _la==scsParser.T__0:
+                self.state = 48
+                localctx.v = self.match(scsParser.T__0)
+
+
+            self.state = 51
+            localctx._CONTENT_BODY = self.match(scsParser.CONTENT_BODY)
+
+            token_context = create_token_context(localctx._CONTENT_BODY)
+            localctx.el = self._impl.create_link(token_context, (None if localctx._CONTENT_BODY is None else localctx._CONTENT_BODY.text)[1:-1], Link.Type.STRING, localctx.v is not None)
+
+        except RecognitionException as re:
+            localctx.exception = re
+            self._errHandler.reportError(self, re)
+            self._errHandler.recover(self, re)
+        finally:
+            self.exitRule()
+        return localctx
+
+
+    class ContourContext(ParserRuleContext):
+        __slots__ = 'parser'
+
+        def __init__(self, parser, parent:ParserRuleContext=None, invokingState:int=-1):
+            super().__init__(parent, invokingState)
+            self.parser = parser
+            self.el = None
+            self._CONTOUR_BEGIN = None # Token
+
+        def CONTOUR_BEGIN(self):
+            return self.getToken(scsParser.CONTOUR_BEGIN, 0)
+
+        def CONTOUR_END(self):
+            return self.getToken(scsParser.CONTOUR_END, 0)
+
+        def sentence_wrap(self, i:int=None):
+            if i is None:
+                return self.getTypedRuleContexts(scsParser.Sentence_wrapContext)
+            else:
+                return self.getTypedRuleContext(scsParser.Sentence_wrapContext,i)
+
+
+        def getRuleIndex(self):
+            return scsParser.RULE_contour
+
+
+
+
+    def contour(self):
+
+        localctx = scsParser.ContourContext(self, self._ctx, self.state)
+        self.enterRule(localctx, 2, self.RULE_contour)
+        count = 1
+        self._la = 0 # Token type
+        try:
+            self.enterOuterAlt(localctx, 1)
+            self.state = 54
+            localctx._CONTOUR_BEGIN = self.match(scsParser.CONTOUR_BEGIN)
+            self.state = 55
+            if not count > 0:
+                from antlr4.error.Errors import FailedPredicateException
+                raise FailedPredicateException(self, "count > 0")
+            self._impl.start_contour()
+
+            self.state = 60
+            self._errHandler.sync(self)
+            _la = self._input.LA(1)
+            while (((_la) & ~0x3f) == 0 and ((1 << _la) & ((1 << scsParser.T__0) | (1 << scsParser.T__39) | (1 << scsParser.T__41) | (1 << scsParser.T__44) | (1 << scsParser.ID_SYSTEM) | (1 << scsParser.ALIAS_SYMBOLS) | (1 << scsParser.CONTOUR_BEGIN) | (1 << scsParser.CONTENT_BODY) | (1 << scsParser.LINK))) != 0):
+                self.state = 57
+                self.sentence_wrap()
+                self.state = 62
+                self._errHandler.sync(self)
+                _la = self._input.LA(1)
+
+            self.state = 63
+            self.match(scsParser.CONTOUR_END)
+
+            count -= 1
+            if count == 0:
+            	contour = self._impl.create_node(create_token_context(localctx._CONTOUR_BEGIN))
+            	self._impl.end_contour(contour)
+            	localctx.el = contour
+
+        except RecognitionException as re:
+            localctx.exception = re
+            self._errHandler.reportError(self, re)
+            self._errHandler.recover(self, re)
+        finally:
+            self.exitRule()
+        return localctx
+
+
+    class Connector_edgeContext(ParserRuleContext):
+        __slots__ = 'parser'
+
+        def __init__(self, parser, parent:ParserRuleContext=None, invokingState:int=-1):
+            super().__init__(parent, invokingState)
+            self.parser = parser
+            self.el = None
+            self.symbol = None # Token
+
+
+        def getRuleIndex(self):
+            return scsParser.RULE_connector_edge
+
+
+
+
+    def connector_edge(self):
+
+        localctx = scsParser.Connector_edgeContext(self, self._ctx, self.state)
+        self.enterRule(localctx, 4, self.RULE_connector_edge)
+        self._la = 0 # Token type
+        try:
+            self.enterOuterAlt(localctx, 1)
+            self.state = 66
+            localctx.symbol = self._input.LT(1)
+            _la = self._input.LA(1)
+            if not((((_la) & ~0x3f) == 0 and ((1 << _la) & ((1 << scsParser.T__1) | (1 << scsParser.T__2) | (1 << scsParser.T__3) | (1 << scsParser.T__4) | (1 << scsParser.T__5) | (1 << scsParser.T__6) | (1 << scsParser.T__7) | (1 << scsParser.T__8) | (1 << scsParser.T__9) | (1 << scsParser.T__10))) != 0)):
+                localctx.symbol = self._errHandler.recoverInline(self)
+            else:
+                self._errHandler.reportMatch(self)
+                self.consume()
+            localctx.el = self._impl.create_edge(create_token_context(localctx.symbol), (None if localctx.symbol is None else localctx.symbol.text))
+        except RecognitionException as re:
+            localctx.exception = re
+            self._errHandler.reportError(self, re)
+            self._errHandler.recover(self, re)
+        finally:
+            self.exitRule()
+        return localctx
+
+
+    class Connector_arcContext(ParserRuleContext):
+        __slots__ = 'parser'
+
+        def __init__(self, parser, parent:ParserRuleContext=None, invokingState:int=-1):
+            super().__init__(parent, invokingState)
+            self.parser = parser
+            self.el = None
+            self.symbol = None # Token
+
+
+        def getRuleIndex(self):
+            return scsParser.RULE_connector_arc
+
+
+
+
+    def connector_arc(self):
+
+        localctx = scsParser.Connector_arcContext(self, self._ctx, self.state)
+        self.enterRule(localctx, 6, self.RULE_connector_arc)
+        self._la = 0 # Token type
+        try:
+            self.enterOuterAlt(localctx, 1)
+            self.state = 69
+            localctx.symbol = self._input.LT(1)
+            _la = self._input.LA(1)
+            if not((((_la) & ~0x3f) == 0 and ((1 << _la) & ((1 << scsParser.T__11) | (1 << scsParser.T__12) | (1 << scsParser.T__13) | (1 << scsParser.T__14) | (1 << scsParser.T__15) | (1 << scsParser.T__16) | (1 << scsParser.T__17) | (1 << scsParser.T__18) | (1 << scsParser.T__19) | (1 << scsParser.T__20) | (1 << scsParser.T__21) | (1 << scsParser.T__22) | (1 << scsParser.T__23) | (1 << scsParser.T__24) | (1 << scsParser.T__25) | (1 << scsParser.T__26) | (1 << scsParser.T__27) | (1 << scsParser.T__28) | (1 << scsParser.T__29) | (1 << scsParser.T__30) | (1 << scsParser.T__31) | (1 << scsParser.T__32) | (1 << scsParser.T__33) | (1 << scsParser.T__34) | (1 << scsParser.T__35) | (1 << scsParser.T__36) | (1 << scsParser.T__37) | (1 << scsParser.T__38))) != 0)):
+                localctx.symbol = self._errHandler.recoverInline(self)
+            else:
+                self._errHandler.reportMatch(self)
+                self.consume()
+            localctx.el = self._impl.create_arc(create_token_context(localctx.symbol), (None if localctx.symbol is None else localctx.symbol.text))
+        except RecognitionException as re:
+            localctx.exception = re
+            self._errHandler.reportError(self, re)
+            self._errHandler.recover(self, re)
+        finally:
+            self.exitRule()
+        return localctx
+
+
+    class ConnectorContext(ParserRuleContext):
+        __slots__ = 'parser'
+
+        def __init__(self, parser, parent:ParserRuleContext=None, invokingState:int=-1):
+            super().__init__(parent, invokingState)
+            self.parser = parser
+            self.el = None
+            self._connector_edge = None # Connector_edgeContext
+            self._connector_arc = None # Connector_arcContext
+
+        def connector_edge(self):
+            return self.getTypedRuleContext(scsParser.Connector_edgeContext,0)
+
+
+        def connector_arc(self):
+            return self.getTypedRuleContext(scsParser.Connector_arcContext,0)
+
+
+        def getRuleIndex(self):
+            return scsParser.RULE_connector
+
+
+
+
+    def connector(self):
+
+        localctx = scsParser.ConnectorContext(self, self._ctx, self.state)
+        self.enterRule(localctx, 8, self.RULE_connector)
+        try:
+            self.state = 78
+            self._errHandler.sync(self)
+            token = self._input.LA(1)
+            if token in [scsParser.T__1, scsParser.T__2, scsParser.T__3, scsParser.T__4, scsParser.T__5, scsParser.T__6, scsParser.T__7, scsParser.T__8, scsParser.T__9, scsParser.T__10]:
+                self.enterOuterAlt(localctx, 1)
+                self.state = 72
+                localctx._connector_edge = self.connector_edge()
+                localctx.el = localctx._connector_edge.el
+                pass
+            elif token in [scsParser.T__11, scsParser.T__12, scsParser.T__13, scsParser.T__14, scsParser.T__15, scsParser.T__16, scsParser.T__17, scsParser.T__18, scsParser.T__19, scsParser.T__20, scsParser.T__21, scsParser.T__22, scsParser.T__23, scsParser.T__24, scsParser.T__25, scsParser.T__26, scsParser.T__27, scsParser.T__28, scsParser.T__29, scsParser.T__30, scsParser.T__31, scsParser.T__32, scsParser.T__33, scsParser.T__34, scsParser.T__35, scsParser.T__36, scsParser.T__37, scsParser.T__38]:
+                self.enterOuterAlt(localctx, 2)
+                self.state = 75
+                localctx._connector_arc = self.connector_arc()
+                localctx.el = localctx._connector_arc.el
+                pass
+            else:
+                raise NoViableAltException(self)
+
+        except RecognitionException as re:
+            localctx.exception = re
+            self._errHandler.reportError(self, re)
+            self._errHandler.recover(self, re)
+        finally:
+            self.exitRule()
+        return localctx
+
+
+    class SyntaxContext(ParserRuleContext):
+        __slots__ = 'parser'
+
+        def __init__(self, parser, parent:ParserRuleContext=None, invokingState:int=-1):
+            super().__init__(parent, invokingState)
+            self.parser = parser
+
+        def EOF(self):
+            return self.getToken(scsParser.EOF, 0)
+
+        def sentence_wrap(self, i:int=None):
+            if i is None:
+                return self.getTypedRuleContexts(scsParser.Sentence_wrapContext)
+            else:
+                return self.getTypedRuleContext(scsParser.Sentence_wrapContext,i)
+
+
+        def getRuleIndex(self):
+            return scsParser.RULE_syntax
+
+
+
+
+    def syntax(self):
+
+        localctx = scsParser.SyntaxContext(self, self._ctx, self.state)
+        self.enterRule(localctx, 10, self.RULE_syntax)
+        self._la = 0 # Token type
+        try:
+            self.enterOuterAlt(localctx, 1)
+            self.state = 83
+            self._errHandler.sync(self)
+            _la = self._input.LA(1)
+            while (((_la) & ~0x3f) == 0 and ((1 << _la) & ((1 << scsParser.T__0) | (1 << scsParser.T__39) | (1 << scsParser.T__41) | (1 << scsParser.T__44) | (1 << scsParser.ID_SYSTEM) | (1 << scsParser.ALIAS_SYMBOLS) | (1 << scsParser.CONTOUR_BEGIN) | (1 << scsParser.CONTENT_BODY) | (1 << scsParser.LINK))) != 0):
+                self.state = 80
+                self.sentence_wrap()
+                self.state = 85
+                self._errHandler.sync(self)
+                _la = self._input.LA(1)
+
+            self.state = 86
+            self.match(scsParser.EOF)
+        except RecognitionException as re:
+            localctx.exception = re
+            self._errHandler.reportError(self, re)
+            self._errHandler.recover(self, re)
+        finally:
+            self.exitRule()
+        return localctx
+
+
+    class Sentence_wrapContext(ParserRuleContext):
+        __slots__ = 'parser'
+
+        def __init__(self, parser, parent:ParserRuleContext=None, invokingState:int=-1):
+            super().__init__(parent, invokingState)
+            self.parser = parser
+
+        def sentence(self):
+            return self.getTypedRuleContext(scsParser.SentenceContext,0)
+
+
+        def SENTENCE_SEP(self):
+            return self.getToken(scsParser.SENTENCE_SEP, 0)
+
+        def getRuleIndex(self):
+            return scsParser.RULE_sentence_wrap
+
+
+
+
+    def sentence_wrap(self):
+
+        localctx = scsParser.Sentence_wrapContext(self, self._ctx, self.state)
+        self.enterRule(localctx, 12, self.RULE_sentence_wrap)
+        try:
+            self.enterOuterAlt(localctx, 1)
+            self.state = 88
+            self.sentence()
+            self.state = 89
+            self.match(scsParser.SENTENCE_SEP)
+        except RecognitionException as re:
+            localctx.exception = re
+            self._errHandler.reportError(self, re)
+            self._errHandler.recover(self, re)
+        finally:
+            self.exitRule()
+        return localctx
+
+
+    class SentenceContext(ParserRuleContext):
+        __slots__ = 'parser'
+
+        def __init__(self, parser, parent:ParserRuleContext=None, invokingState:int=-1):
+            super().__init__(parent, invokingState)
+            self.parser = parser
+
+        def sentence_assign(self):
+            return self.getTypedRuleContext(scsParser.Sentence_assignContext,0)
+
+
+        def sentence_lvl_common(self):
+            return self.getTypedRuleContext(scsParser.Sentence_lvl_commonContext,0)
+
+
+        def getRuleIndex(self):
+            return scsParser.RULE_sentence
+
+
+
+
+    def sentence(self):
+
+        localctx = scsParser.SentenceContext(self, self._ctx, self.state)
+        self.enterRule(localctx, 14, self.RULE_sentence)
+        try:
+            self.state = 93
+            self._errHandler.sync(self)
+            la_ = self._interp.adaptivePredict(self._input,4,self._ctx)
+            if la_ == 1:
+                self.enterOuterAlt(localctx, 1)
+                self.state = 91
+                self.sentence_assign()
+                pass
+
+            elif la_ == 2:
+                self.enterOuterAlt(localctx, 2)
+                self.state = 92
+                self.sentence_lvl_common()
+                pass
+
+
+        except RecognitionException as re:
+            localctx.exception = re
+            self._errHandler.reportError(self, re)
+            self._errHandler.recover(self, re)
+        finally:
+            self.exitRule()
+        return localctx
+
+
+    class Ifdf_aliasContext(ParserRuleContext):
+        __slots__ = 'parser'
+
+        def __init__(self, parser, parent:ParserRuleContext=None, invokingState:int=-1):
+            super().__init__(parent, invokingState)
+            self.parser = parser
+            self.el = None
+            self._ALIAS_SYMBOLS = None # Token
+
+        def ALIAS_SYMBOLS(self):
+            return self.getToken(scsParser.ALIAS_SYMBOLS, 0)
+
+        def getRuleIndex(self):
+            return scsParser.RULE_ifdf_alias
+
+
+
+
+    def ifdf_alias(self):
+
+        localctx = scsParser.Ifdf_aliasContext(self, self._ctx, self.state)
+        self.enterRule(localctx, 16, self.RULE_ifdf_alias)
+        try:
+            self.enterOuterAlt(localctx, 1)
+            self.state = 95
+            localctx._ALIAS_SYMBOLS = self.match(scsParser.ALIAS_SYMBOLS)
+
+            localctx.el = self._impl.create_alias(create_token_context(localctx._ALIAS_SYMBOLS))
+
+        except RecognitionException as re:
+            localctx.exception = re
+            self._errHandler.reportError(self, re)
+            self._errHandler.recover(self, re)
+        finally:
+            self.exitRule()
+        return localctx
+
+
+    class Idtf_systemContext(ParserRuleContext):
+        __slots__ = 'parser'
+
+        def __init__(self, parser, parent:ParserRuleContext=None, invokingState:int=-1):
+            super().__init__(parent, invokingState)
+            self.parser = parser
+            self.el = None
+            self.value = None # Token
+
+        def ID_SYSTEM(self):
+            return self.getToken(scsParser.ID_SYSTEM, 0)
+
+        def getRuleIndex(self):
+            return scsParser.RULE_idtf_system
+
+
+
+
+    def idtf_system(self):
+
+        localctx = scsParser.Idtf_systemContext(self, self._ctx, self.state)
+        self.enterRule(localctx, 18, self.RULE_idtf_system)
+        self._la = 0 # Token type
+        try:
+            self.enterOuterAlt(localctx, 1)
+            self.state = 98
+            localctx.value = self._input.LT(1)
+            _la = self._input.LA(1)
+            if not(_la==scsParser.T__39 or _la==scsParser.ID_SYSTEM):
+                localctx.value = self._errHandler.recoverInline(self)
+            else:
+                self._errHandler.reportMatch(self)
+                self.consume()
+
+            localctx.el = self._impl.create_node(create_token_context(localctx.value))
+
+        except RecognitionException as re:
+            localctx.exception = re
+            self._errHandler.reportError(self, re)
+            self._errHandler.recover(self, re)
+        finally:
+            self.exitRule()
+        return localctx
+
+
+    class Sentence_assignContext(ParserRuleContext):
+        __slots__ = 'parser'
+
+        def __init__(self, parser, parent:ParserRuleContext=None, invokingState:int=-1):
+            super().__init__(parent, invokingState)
+            self.parser = parser
+            self._ALIAS_SYMBOLS = None # Token
+            self._idtf_common = None # Idtf_commonContext
+
+        def ALIAS_SYMBOLS(self):
+            return self.getToken(scsParser.ALIAS_SYMBOLS, 0)
+
+        def idtf_common(self):
+            return self.getTypedRuleContext(scsParser.Idtf_commonContext,0)
+
+
+        def getRuleIndex(self):
+            return scsParser.RULE_sentence_assign
+
+
+
+
+    def sentence_assign(self):
+
+        localctx = scsParser.Sentence_assignContext(self, self._ctx, self.state)
+        self.enterRule(localctx, 20, self.RULE_sentence_assign)
+        try:
+            self.enterOuterAlt(localctx, 1)
+            self.state = 101
+            localctx._ALIAS_SYMBOLS = self.match(scsParser.ALIAS_SYMBOLS)
+            self.state = 102
+            self.match(scsParser.T__40)
+            self.state = 103
+            localctx._idtf_common = self.idtf_common()
+
+
+            context = create_token_context(localctx._ALIAS_SYMBOLS)
+            self._impl.define_alias(self._impl.create_alias(context), localctx._idtf_common.el)
+
+        except RecognitionException as re:
+            localctx.exception = re
+            self._errHandler.reportError(self, re)
+            self._errHandler.recover(self, re)
+        finally:
+            self.exitRule()
+        return localctx
+
+
+    class Idtf_edgeContext(ParserRuleContext):
+        __slots__ = 'parser'
+
+        def __init__(self, parser, parent:ParserRuleContext=None, invokingState:int=-1):
+            super().__init__(parent, invokingState)
+            self.parser = parser
+            self.el = None
+            self.src = None # Idtf_atomicContext
+            self._connector = None # ConnectorContext
+            self.attr = None # Attr_listContext
+            self.trg = None # Idtf_atomicContext
+
+        def connector(self):
+            return self.getTypedRuleContext(scsParser.ConnectorContext,0)
+
+
+        def idtf_atomic(self, i:int=None):
+            if i is None:
+                return self.getTypedRuleContexts(scsParser.Idtf_atomicContext)
+            else:
+                return self.getTypedRuleContext(scsParser.Idtf_atomicContext,i)
+
+
+        def attr_list(self):
+            return self.getTypedRuleContext(scsParser.Attr_listContext,0)
+
+
+        def getRuleIndex(self):
+            return scsParser.RULE_idtf_edge
+
+
+
+
+    def idtf_edge(self):
+
+        localctx = scsParser.Idtf_edgeContext(self, self._ctx, self.state)
+        self.enterRule(localctx, 22, self.RULE_idtf_edge)
+        try:
+            self.enterOuterAlt(localctx, 1)
+            self.state = 106
+            self.match(scsParser.T__41)
+            self.state = 107
+            localctx.src = self.idtf_atomic()
+            self.state = 108
+            localctx._connector = self.connector()
+            self.state = 110
+            self._errHandler.sync(self)
+            la_ = self._interp.adaptivePredict(self._input,5,self._ctx)
+            if la_ == 1:
+                self.state = 109
+                localctx.attr = self.attr_list()
+
+
+            self.state = 112
+            localctx.trg = self.idtf_atomic()
+            self.state = 113
+            self.match(scsParser.T__42)
+
+            self._impl.append_triple(localctx.src.el, localctx._connector.el, localctx.trg.el)
+            localctx.el = localctx._connector.el
+
+            if localctx.attr is not None:
+            	for a, e in localctx.attr.items:
+            		self._impl.append_triple(a, e, localctx._connector.el)
+
+        except RecognitionException as re:
+            localctx.exception = re
+            self._errHandler.reportError(self, re)
+            self._errHandler.recover(self, re)
+        finally:
+            self.exitRule()
+        return localctx
+
+
+    class Idtf_set_itemContext(ParserRuleContext):
+        __slots__ = 'parser'
+
+        def __init__(self, parser, parent:ParserRuleContext=None, invokingState:int=-1, set:Element=None):
+            super().__init__(parent, invokingState)
+            self.parser = parser
+            self.set = None
+            self.attr = None # Attr_listContext
+            self.idtf = None # Idtf_commonContext
+            self.set = set
+
+        def idtf_common(self):
+            return self.getTypedRuleContext(scsParser.Idtf_commonContext,0)
+
+
+        def attr_list(self):
+            return self.getTypedRuleContext(scsParser.Attr_listContext,0)
+
+
+        def getRuleIndex(self):
+            return scsParser.RULE_idtf_set_item
+
+
+
+
+    def idtf_set_item(self, set:Element):
+
+        localctx = scsParser.Idtf_set_itemContext(self, self._ctx, self.state, set)
+        self.enterRule(localctx, 24, self.RULE_idtf_set_item)
+        try:
+            self.enterOuterAlt(localctx, 1)
+            self.state = 117
+            self._errHandler.sync(self)
+            la_ = self._interp.adaptivePredict(self._input,6,self._ctx)
+            if la_ == 1:
+                self.state = 116
+                localctx.attr = self.attr_list()
+
+
+            self.state = 119
+            localctx.idtf = self.idtf_common()
+
+            edge = self._impl.create_arc(localctx.idtf.el.ctx.clone(), '->')
+            self._impl.append_triple(localctx.set, edge, localctx.idtf.el)
+            if localctx.attr is not None:
+            	for a, e in localctx.attr.items:
+            		self._impl.append_triple(a, e, edge)
+
+        except RecognitionException as re:
+            localctx.exception = re
+            self._errHandler.reportError(self, re)
+            self._errHandler.recover(self, re)
+        finally:
+            self.exitRule()
+        return localctx
+
+
+    class Idtf_set_item_listContext(ParserRuleContext):
+        __slots__ = 'parser'
+
+        def __init__(self, parser, parent:ParserRuleContext=None, invokingState:int=-1, set:Element=None):
+            super().__init__(parent, invokingState)
+            self.parser = parser
+            self.set = None
+            self.set = set
+
+        def idtf_set_item(self, i:int=None):
+            if i is None:
+                return self.getTypedRuleContexts(scsParser.Idtf_set_itemContext)
+            else:
+                return self.getTypedRuleContext(scsParser.Idtf_set_itemContext,i)
+
+
+        def getRuleIndex(self):
+            return scsParser.RULE_idtf_set_item_list
+
+
+
+
+    def idtf_set_item_list(self, set:Element):
+
+        localctx = scsParser.Idtf_set_item_listContext(self, self._ctx, self.state, set)
+        self.enterRule(localctx, 26, self.RULE_idtf_set_item_list)
+        self._la = 0 # Token type
+        try:
+            self.enterOuterAlt(localctx, 1)
+            self.state = 122
+            self.idtf_set_item(set)
+            self.state = 127
+            self._errHandler.sync(self)
+            _la = self._input.LA(1)
+            while _la==scsParser.T__43:
+                self.state = 123
+                self.match(scsParser.T__43)
+                self.state = 124
+                self.idtf_set_item(set)
+                self.state = 129
+                self._errHandler.sync(self)
+                _la = self._input.LA(1)
+
+        except RecognitionException as re:
+            localctx.exception = re
+            self._errHandler.reportError(self, re)
+            self._errHandler.recover(self, re)
+        finally:
+            self.exitRule()
+        return localctx
+
+
+    class Idtf_setContext(ParserRuleContext):
+        __slots__ = 'parser'
+
+        def __init__(self, parser, parent:ParserRuleContext=None, invokingState:int=-1):
+            super().__init__(parent, invokingState)
+            self.parser = parser
+            self.el = None
+            self.t = None # Token
+
+        def idtf_set_item_list(self):
+            return self.getTypedRuleContext(scsParser.Idtf_set_item_listContext,0)
+
+
+        def getRuleIndex(self):
+            return scsParser.RULE_idtf_set
+
+
+
+
+    def idtf_set(self):
+
+        localctx = scsParser.Idtf_setContext(self, self._ctx, self.state)
+        self.enterRule(localctx, 28, self.RULE_idtf_set)
+        try:
+            self.enterOuterAlt(localctx, 1)
+            self.state = 130
+            localctx.t = self.match(scsParser.T__44)
+
+            context = create_token_context(localctx.t)
+            localctx.el = self._impl.create_node(context)
+            	
+            self.state = 132
+            self.idtf_set_item_list(localctx.el)
+            self.state = 133
+            self.match(scsParser.T__45)
+        except RecognitionException as re:
+            localctx.exception = re
+            self._errHandler.reportError(self, re)
+            self._errHandler.recover(self, re)
+        finally:
+            self.exitRule()
+        return localctx
+
+
+    class Idtf_atomicContext(ParserRuleContext):
+        __slots__ = 'parser'
+
+        def __init__(self, parser, parent:ParserRuleContext=None, invokingState:int=-1):
+            super().__init__(parent, invokingState)
+            self.parser = parser
+            self.el = None
+            self._ifdf_alias = None # Ifdf_aliasContext
+            self._idtf_system = None # Idtf_systemContext
+
+        def ifdf_alias(self):
+            return self.getTypedRuleContext(scsParser.Ifdf_aliasContext,0)
+
+
+        def idtf_system(self):
+            return self.getTypedRuleContext(scsParser.Idtf_systemContext,0)
+
+
+        def getRuleIndex(self):
+            return scsParser.RULE_idtf_atomic
+
+
+
+
+    def idtf_atomic(self):
+
+        localctx = scsParser.Idtf_atomicContext(self, self._ctx, self.state)
+        self.enterRule(localctx, 30, self.RULE_idtf_atomic)
+        try:
+            self.state = 141
+            self._errHandler.sync(self)
+            token = self._input.LA(1)
+            if token in [scsParser.ALIAS_SYMBOLS]:
+                self.enterOuterAlt(localctx, 1)
+                self.state = 135
+                localctx._ifdf_alias = self.ifdf_alias()
+                localctx.el = localctx._ifdf_alias.el
+                pass
+            elif token in [scsParser.T__39, scsParser.ID_SYSTEM]:
+                self.enterOuterAlt(localctx, 2)
+                self.state = 138
+                localctx._idtf_system = self.idtf_system()
+                localctx.el = localctx._idtf_system.el
+                pass
+            else:
+                raise NoViableAltException(self)
+
+        except RecognitionException as re:
+            localctx.exception = re
+            self._errHandler.reportError(self, re)
+            self._errHandler.recover(self, re)
+        finally:
+            self.exitRule()
+        return localctx
+
+
+    class Idtf_urlContext(ParserRuleContext):
+        __slots__ = 'parser'
+
+        def __init__(self, parser, parent:ParserRuleContext=None, invokingState:int=-1):
+            super().__init__(parent, invokingState)
+            self.parser = parser
+            self.el = None
+            self._LINK = None # Token
+
+        def LINK(self):
+            return self.getToken(scsParser.LINK, 0)
+
+        def getRuleIndex(self):
+            return scsParser.RULE_idtf_url
+
+
+
+
+    def idtf_url(self):
+
+        localctx = scsParser.Idtf_urlContext(self, self._ctx, self.state)
+        self.enterRule(localctx, 32, self.RULE_idtf_url)
+        try:
+            self.enterOuterAlt(localctx, 1)
+            self.state = 143
+            localctx._LINK = self.match(scsParser.LINK)
+
+            context = create_token_context(localctx._LINK)
+            localctx.el = self._impl.create_link(context, (None if localctx._LINK is None else localctx._LINK.text)[1:-1], Link.Type.URL, False)
+
+        except RecognitionException as re:
+            localctx.exception = re
+            self._errHandler.reportError(self, re)
+            self._errHandler.recover(self, re)
+        finally:
+            self.exitRule()
+        return localctx
+
+
+    class Idtf_commonContext(ParserRuleContext):
+        __slots__ = 'parser'
+
+        def __init__(self, parser, parent:ParserRuleContext=None, invokingState:int=-1):
+            super().__init__(parent, invokingState)
+            self.parser = parser
+            self.el = None
+            self._idtf_atomic = None # Idtf_atomicContext
+            self._idtf_edge = None # Idtf_edgeContext
+            self._idtf_set = None # Idtf_setContext
+            self._contour = None # ContourContext
+            self._content = None # ContentContext
+            self._idtf_url = None # Idtf_urlContext
+
+        def idtf_atomic(self):
+            return self.getTypedRuleContext(scsParser.Idtf_atomicContext,0)
+
+
+        def idtf_edge(self):
+            return self.getTypedRuleContext(scsParser.Idtf_edgeContext,0)
+
+
+        def idtf_set(self):
+            return self.getTypedRuleContext(scsParser.Idtf_setContext,0)
+
+
+        def contour(self):
+            return self.getTypedRuleContext(scsParser.ContourContext,0)
+
+
+        def content(self):
+            return self.getTypedRuleContext(scsParser.ContentContext,0)
+
+
+        def idtf_url(self):
+            return self.getTypedRuleContext(scsParser.Idtf_urlContext,0)
+
+
+        def getRuleIndex(self):
+            return scsParser.RULE_idtf_common
+
+
+
+
+    def idtf_common(self):
+
+        localctx = scsParser.Idtf_commonContext(self, self._ctx, self.state)
+        self.enterRule(localctx, 34, self.RULE_idtf_common)
+        try:
+            self.state = 164
+            self._errHandler.sync(self)
+            token = self._input.LA(1)
+            if token in [scsParser.T__39, scsParser.ID_SYSTEM, scsParser.ALIAS_SYMBOLS]:
+                self.enterOuterAlt(localctx, 1)
+                self.state = 146
+                localctx._idtf_atomic = self.idtf_atomic()
+                localctx.el = localctx._idtf_atomic.el
+                pass
+            elif token in [scsParser.T__41]:
+                self.enterOuterAlt(localctx, 2)
+                self.state = 149
+                localctx._idtf_edge = self.idtf_edge()
+                localctx.el = localctx._idtf_edge.el
+                pass
+            elif token in [scsParser.T__44]:
+                self.enterOuterAlt(localctx, 3)
+                self.state = 152
+                localctx._idtf_set = self.idtf_set()
+                localctx.el = localctx._idtf_set.el
+                pass
+            elif token in [scsParser.CONTOUR_BEGIN]:
+                self.enterOuterAlt(localctx, 4)
+                self.state = 155
+                localctx._contour = self.contour()
+                localctx.el = localctx._contour.el
+                pass
+            elif token in [scsParser.T__0, scsParser.CONTENT_BODY]:
+                self.enterOuterAlt(localctx, 5)
+                self.state = 158
+                localctx._content = self.content()
+                localctx.el = localctx._content.el
+                pass
+            elif token in [scsParser.LINK]:
+                self.enterOuterAlt(localctx, 6)
+                self.state = 161
+                localctx._idtf_url = self.idtf_url()
+                localctx.el = localctx._idtf_url.el
+                pass
+            else:
+                raise NoViableAltException(self)
+
+        except RecognitionException as re:
+            localctx.exception = re
+            self._errHandler.reportError(self, re)
+            self._errHandler.recover(self, re)
+        finally:
+            self.exitRule()
+        return localctx
+
+
+    class Idtf_listContext(ParserRuleContext):
+        __slots__ = 'parser'
+
+        def __init__(self, parser, parent:ParserRuleContext=None, invokingState:int=-1):
+            super().__init__(parent, invokingState)
+            self.parser = parser
+            self.items = None
+            self.first = None # Idtf_commonContext
+            self.second = None # Idtf_commonContext
+
+        def idtf_common(self, i:int=None):
+            if i is None:
+                return self.getTypedRuleContexts(scsParser.Idtf_commonContext)
+            else:
+                return self.getTypedRuleContext(scsParser.Idtf_commonContext,i)
+
+
+        def internal_sentence_list(self, i:int=None):
+            if i is None:
+                return self.getTypedRuleContexts(scsParser.Internal_sentence_listContext)
+            else:
+                return self.getTypedRuleContext(scsParser.Internal_sentence_listContext,i)
+
+
+        def getRuleIndex(self):
+            return scsParser.RULE_idtf_list
+
+
+
+
+    def idtf_list(self):
+
+        localctx = scsParser.Idtf_listContext(self, self._ctx, self.state)
+        self.enterRule(localctx, 36, self.RULE_idtf_list)
+        localctx.items = []
+        self._la = 0 # Token type
+        try:
+            self.enterOuterAlt(localctx, 1)
+            self.state = 166
+            localctx.first = self.idtf_common()
+            localctx.items.append(localctx.first.el)
+            self.state = 169
+            self._errHandler.sync(self)
+            _la = self._input.LA(1)
+            if _la==scsParser.T__46:
+                self.state = 168
+                self.internal_sentence_list(localctx.first.el)
+
+
+            self.state = 179
+            self._errHandler.sync(self)
+            _alt = self._interp.adaptivePredict(self._input,12,self._ctx)
+            while _alt!=2 and _alt!=ATN.INVALID_ALT_NUMBER:
+                if _alt==1:
+                    self.state = 171
+                    self.match(scsParser.T__43)
+                    self.state = 172
+                    localctx.second = self.idtf_common()
+                    localctx.items.append(localctx.second.el)
+                    self.state = 175
+                    self._errHandler.sync(self)
+                    _la = self._input.LA(1)
+                    if _la==scsParser.T__46:
+                        self.state = 174
+                        self.internal_sentence_list(localctx.first.el)
+
+             
+                self.state = 181
+                self._errHandler.sync(self)
+                _alt = self._interp.adaptivePredict(self._input,12,self._ctx)
+
+        except RecognitionException as re:
+            localctx.exception = re
+            self._errHandler.reportError(self, re)
+            self._errHandler.recover(self, re)
+        finally:
+            self.exitRule()
+        return localctx
+
+
+    class Internal_sentenceContext(ParserRuleContext):
+        __slots__ = 'parser'
+
+        def __init__(self, parser, parent:ParserRuleContext=None, invokingState:int=-1, src:Element=None):
+            super().__init__(parent, invokingState)
+            self.parser = parser
+            self.src = None
+            self.c = None # ConnectorContext
+            self.attr = None # Attr_listContext
+            self.target = None # Idtf_listContext
+            self.src = src
+
+        def connector(self):
+            return self.getTypedRuleContext(scsParser.ConnectorContext,0)
+
+
+        def idtf_list(self):
+            return self.getTypedRuleContext(scsParser.Idtf_listContext,0)
+
+
+        def attr_list(self):
+            return self.getTypedRuleContext(scsParser.Attr_listContext,0)
+
+
+        def getRuleIndex(self):
+            return scsParser.RULE_internal_sentence
+
+
+
+
+    def internal_sentence(self, src:Element):
+
+        localctx = scsParser.Internal_sentenceContext(self, self._ctx, self.state, src)
+        self.enterRule(localctx, 38, self.RULE_internal_sentence)
+        try:
+            self.enterOuterAlt(localctx, 1)
+            self.state = 182
+            localctx.c = self.connector()
+            self.state = 184
+            self._errHandler.sync(self)
+            la_ = self._interp.adaptivePredict(self._input,13,self._ctx)
+            if la_ == 1:
+                self.state = 183
+                localctx.attr = self.attr_list()
+
+
+            self.state = 186
+            localctx.target = self.idtf_list()
+
+
+            for t in localctx.target.items:
+            	edge = None
+            	if isinstance(localctx.c.el, Edge):
+            		edge = self._impl.create_edge(localctx.c.el.ctx, localctx.c.el.connector)
+            	else:
+            		edge = self._impl.create_arc(localctx.c.el.ctx, localctx.c.el.connector)
+            	self._impl.append_triple(localctx.src, edge, t)
+            	if localctx.attr is not None:
+            		for a, e in localctx.attr.items:
+            			self._impl.append_triple(a, e, edge)
+
+
+        except RecognitionException as re:
+            localctx.exception = re
+            self._errHandler.reportError(self, re)
+            self._errHandler.recover(self, re)
+        finally:
+            self.exitRule()
+        return localctx
+
+
+    class Internal_sentence_listContext(ParserRuleContext):
+        __slots__ = 'parser'
+
+        def __init__(self, parser, parent:ParserRuleContext=None, invokingState:int=-1, src:Element=None):
+            super().__init__(parent, invokingState)
+            self.parser = parser
+            self.src = None
+            self.src = src
+
+        def internal_sentence(self, i:int=None):
+            if i is None:
+                return self.getTypedRuleContexts(scsParser.Internal_sentenceContext)
+            else:
+                return self.getTypedRuleContext(scsParser.Internal_sentenceContext,i)
+
+
+        def SENTENCE_SEP(self, i:int=None):
+            if i is None:
+                return self.getTokens(scsParser.SENTENCE_SEP)
+            else:
+                return self.getToken(scsParser.SENTENCE_SEP, i)
+
+        def getRuleIndex(self):
+            return scsParser.RULE_internal_sentence_list
+
+
+
+
+    def internal_sentence_list(self, src:Element):
+
+        localctx = scsParser.Internal_sentence_listContext(self, self._ctx, self.state, src)
+        self.enterRule(localctx, 40, self.RULE_internal_sentence_list)
+        self._la = 0 # Token type
+        try:
+            self.enterOuterAlt(localctx, 1)
+            self.state = 189
+            self.match(scsParser.T__46)
+            self.state = 193 
+            self._errHandler.sync(self)
+            _la = self._input.LA(1)
+            while True:
+                self.state = 190
+                self.internal_sentence(src)
+                self.state = 191
+                self.match(scsParser.SENTENCE_SEP)
+                self.state = 195 
+                self._errHandler.sync(self)
+                _la = self._input.LA(1)
+                if not ((((_la) & ~0x3f) == 0 and ((1 << _la) & ((1 << scsParser.T__1) | (1 << scsParser.T__2) | (1 << scsParser.T__3) | (1 << scsParser.T__4) | (1 << scsParser.T__5) | (1 << scsParser.T__6) | (1 << scsParser.T__7) | (1 << scsParser.T__8) | (1 << scsParser.T__9) | (1 << scsParser.T__10) | (1 << scsParser.T__11) | (1 << scsParser.T__12) | (1 << scsParser.T__13) | (1 << scsParser.T__14) | (1 << scsParser.T__15) | (1 << scsParser.T__16) | (1 << scsParser.T__17) | (1 << scsParser.T__18) | (1 << scsParser.T__19) | (1 << scsParser.T__20) | (1 << scsParser.T__21) | (1 << scsParser.T__22) | (1 << scsParser.T__23) | (1 << scsParser.T__24) | (1 << scsParser.T__25) | (1 << scsParser.T__26) | (1 << scsParser.T__27) | (1 << scsParser.T__28) | (1 << scsParser.T__29) | (1 << scsParser.T__30) | (1 << scsParser.T__31) | (1 << scsParser.T__32) | (1 << scsParser.T__33) | (1 << scsParser.T__34) | (1 << scsParser.T__35) | (1 << scsParser.T__36) | (1 << scsParser.T__37) | (1 << scsParser.T__38))) != 0)):
+                    break
+
+            self.state = 197
+            self.match(scsParser.T__47)
+        except RecognitionException as re:
+            localctx.exception = re
+            self._errHandler.reportError(self, re)
+            self._errHandler.recover(self, re)
+        finally:
+            self.exitRule()
+        return localctx
+
+
+    class Sentence_lvl_4_list_itemContext(ParserRuleContext):
+        __slots__ = 'parser'
+
+        def __init__(self, parser, parent:ParserRuleContext=None, invokingState:int=-1, src:Element=None):
+            super().__init__(parent, invokingState)
+            self.parser = parser
+            self.src = None
+            self.c = None # ConnectorContext
+            self.attr = None # Attr_listContext
+            self.target = None # Idtf_listContext
+            self.src = src
+
+        def connector(self):
+            return self.getTypedRuleContext(scsParser.ConnectorContext,0)
+
+
+        def idtf_list(self):
+            return self.getTypedRuleContext(scsParser.Idtf_listContext,0)
+
+
+        def attr_list(self):
+            return self.getTypedRuleContext(scsParser.Attr_listContext,0)
+
+
+        def getRuleIndex(self):
+            return scsParser.RULE_sentence_lvl_4_list_item
+
+
+
+
+    def sentence_lvl_4_list_item(self, src:Element):
+
+        localctx = scsParser.Sentence_lvl_4_list_itemContext(self, self._ctx, self.state, src)
+        self.enterRule(localctx, 42, self.RULE_sentence_lvl_4_list_item)
+        try:
+            self.enterOuterAlt(localctx, 1)
+            self.state = 199
+            localctx.c = self.connector()
+            self.state = 201
+            self._errHandler.sync(self)
+            la_ = self._interp.adaptivePredict(self._input,15,self._ctx)
+            if la_ == 1:
+                self.state = 200
+                localctx.attr = self.attr_list()
+
+
+            self.state = 203
+            localctx.target = self.idtf_list()
+
+            for t in localctx.target.items:
+            	edge = None
+            	if isinstance(localctx.c.el, Edge):
+            		edge = self._impl.create_edge(localctx.c.el.ctx, localctx.c.el.connector)
+            	else:
+            		edge = self._impl.create_arc(localctx.c.el.ctx, localctx.c.el.connector)
+
+            	self._impl.append_triple(localctx.src, edge, t)
+            	if localctx.attr is not None:
+            		for a, e in localctx.attr.items:
+            			self._impl.append_triple(a, e, edge)
+
+        except RecognitionException as re:
+            localctx.exception = re
+            self._errHandler.reportError(self, re)
+            self._errHandler.recover(self, re)
+        finally:
+            self.exitRule()
+        return localctx
+
+
+    class Sentence_lvl_commonContext(ParserRuleContext):
+        __slots__ = 'parser'
+
+        def __init__(self, parser, parent:ParserRuleContext=None, invokingState:int=-1):
+            super().__init__(parent, invokingState)
+            self.parser = parser
+            self._idtf_common = None # Idtf_commonContext
+
+        def idtf_common(self):
+            return self.getTypedRuleContext(scsParser.Idtf_commonContext,0)
+
+
+        def sentence_lvl_4_list_item(self, i:int=None):
+            if i is None:
+                return self.getTypedRuleContexts(scsParser.Sentence_lvl_4_list_itemContext)
+            else:
+                return self.getTypedRuleContext(scsParser.Sentence_lvl_4_list_itemContext,i)
+
+
+        def getRuleIndex(self):
+            return scsParser.RULE_sentence_lvl_common
+
+
+
+
+    def sentence_lvl_common(self):
+
+        localctx = scsParser.Sentence_lvl_commonContext(self, self._ctx, self.state)
+        self.enterRule(localctx, 44, self.RULE_sentence_lvl_common)
+        self._la = 0 # Token type
+        try:
+            self.enterOuterAlt(localctx, 1)
+            self.state = 207
+            localctx._idtf_common = self.idtf_common()
+            self.state = 208
+            self.sentence_lvl_4_list_item(localctx._idtf_common.el)
+            self.state = 213
+            self._errHandler.sync(self)
+            _la = self._input.LA(1)
+            while _la==scsParser.T__43:
+                self.state = 209
+                self.match(scsParser.T__43)
+                self.state = 210
+                self.sentence_lvl_4_list_item(localctx._idtf_common.el)
+                self.state = 215
+                self._errHandler.sync(self)
+                _la = self._input.LA(1)
+
+        except RecognitionException as re:
+            localctx.exception = re
+            self._errHandler.reportError(self, re)
+            self._errHandler.recover(self, re)
+        finally:
+            self.exitRule()
+        return localctx
+
+
+    class Attr_listContext(ParserRuleContext):
+        __slots__ = 'parser'
+
+        def __init__(self, parser, parent:ParserRuleContext=None, invokingState:int=-1):
+            super().__init__(parent, invokingState)
+            self.parser = parser
+            self.items = None
+            self._ID_SYSTEM = None # Token
+            self._EDGE_ATTR = None # Token
+
+        def ID_SYSTEM(self, i:int=None):
+            if i is None:
+                return self.getTokens(scsParser.ID_SYSTEM)
+            else:
+                return self.getToken(scsParser.ID_SYSTEM, i)
+
+        def EDGE_ATTR(self, i:int=None):
+            if i is None:
+                return self.getTokens(scsParser.EDGE_ATTR)
+            else:
+                return self.getToken(scsParser.EDGE_ATTR, i)
+
+        def getRuleIndex(self):
+            return scsParser.RULE_attr_list
+
+
+
+
+    def attr_list(self):
+
+        localctx = scsParser.Attr_listContext(self, self._ctx, self.state)
+        self.enterRule(localctx, 46, self.RULE_attr_list)
+        localctx.items = []
+        try:
+            self.enterOuterAlt(localctx, 1)
+            self.state = 219 
+            self._errHandler.sync(self)
+            _alt = 1
+            while _alt!=2 and _alt!=ATN.INVALID_ALT_NUMBER:
+                if _alt == 1:
+                    self.state = 216
+                    localctx._ID_SYSTEM = self.match(scsParser.ID_SYSTEM)
+                    self.state = 217
+                    localctx._EDGE_ATTR = self.match(scsParser.EDGE_ATTR)
+
+                    node = self._impl.create_node(create_token_context(localctx._ID_SYSTEM))
+                    edge = None
+                    connector = "->" if (None if localctx._EDGE_ATTR is None else localctx._EDGE_ATTR.text) == ":" else "_->"
+                    edge = self._impl.create_arc(create_token_context(localctx._EDGE_ATTR), connector)
+
+                    localctx.items.append((node, edge))
+
+
+                else:
+                    raise NoViableAltException(self)
+                self.state = 221 
+                self._errHandler.sync(self)
+                _alt = self._interp.adaptivePredict(self._input,17,self._ctx)
+
+        except RecognitionException as re:
+            localctx.exception = re
+            self._errHandler.reportError(self, re)
+            self._errHandler.recover(self, re)
+        finally:
+            self.exitRule()
+        return localctx
+
+
+
+    def sempred(self, localctx:RuleContext, ruleIndex:int, predIndex:int):
+        if self._predicates == None:
+            self._predicates = dict()
+        self._predicates[1] = self.contour_sempred
+        pred = self._predicates.get(ruleIndex, None)
+        if pred is None:
+            raise Exception("No predicate with index:" + str(ruleIndex))
+        else:
+            return pred(localctx, predIndex)
+
+    def contour_sempred(self, localctx:ContourContext, predIndex:int):
+            if predIndex == 0:
+                return count > 0
+         
+
+
+
+
diff --git a/db/sc/scs/error.py b/db/sc/scs/error.py
new file mode 100644
index 0000000..dca6a1a
--- /dev/null
+++ b/db/sc/scs/error.py
@@ -0,0 +1,7 @@
+
+class AlreadyExistError(Exception):
+    pass
+
+
+class UnsupportedError(Exception):
+    pass
diff --git a/db/sc/scs/parse_issue.py b/db/sc/scs/parse_issue.py
new file mode 100644
index 0000000..01a1503
--- /dev/null
+++ b/db/sc/scs/parse_issue.py
@@ -0,0 +1,19 @@
+from enum import Enum
+
+
+class ParseIssue:
+    class Type(Enum):
+        WARNING = 1
+        ERROR = 2
+
+    def __init__(self, line: int, char_pos: int, token: str, msg: str, type: Type) -> None:
+        self._line = line
+        self._char_pos = char_pos
+        self._token = token
+        self._msg = msg
+        self._type = type
+
+    def __repr__(self) -> str:
+        token = self._token if self._token is not None else ""
+        return (f"{self._type.name}: {self._msg}. "
+                f"Line {self._line}:{self._char_pos} - '{token}'")
diff --git a/db/sc/scs/parser.py b/db/sc/scs/parser.py
new file mode 100644
index 0000000..35e9e68
--- /dev/null
+++ b/db/sc/scs/parser.py
@@ -0,0 +1,116 @@
+import antlr4
+
+from antlr4.error.Errors import ParseCancellationException
+from antlr4.error.ErrorListener import ErrorListener, ConsoleErrorListener
+from antlr4.error.ErrorStrategy import BailErrorStrategy
+
+from enum import Enum
+from typing import List, Tuple
+
+
+from .antlr import SCsLexerAntlr, SCsParserAntlr
+from .parse_issue import ParseIssue
+from .parser_impl import SCsParserImpl, Triple
+
+
+class SCsParser:
+
+    class SyntaxErrorListener(ErrorListener):
+
+        def __init__(self) -> None:
+            super().__init__()
+            self._errors = []
+
+        @property
+        def errors(self):
+            return self._errors
+
+        def syntaxError(self, recognizer, offendingSymbol, line, column, msg, e):
+            error = ParseIssue(
+                line=line,
+                char_pos=column,
+                token=e.offendingToken.text if e.offendingToken else None,
+                msg=msg,
+                type=ParseIssue.Type.ERROR)
+
+            self._errors.append(error)
+
+    def __init__(self) -> None:
+        self._error_listener = SCsParser.SyntaxErrorListener()
+        self._impl = SCsParserImpl()
+        self._errors = []
+        self._warnings = []
+
+    @property
+    def errors(self) -> List[ParseIssue]:
+        """Returns list of errors"""
+        return self._errors
+
+    @property
+    def warnings(self) -> List[ParseIssue]:
+        """Returns list of warnings"""
+        return self._warnings
+
+    @property
+    def triples(self) -> List[Triple]:
+        """Returns list of parsed triples in format (src, edge, trg)"""
+        return self._impl.triples
+
+    @property
+    def type_triples(self) -> List[Tuple]:
+        """Returns list of parsed type triples in format (src, edge, trg).
+
+        Source of each triple is a keynode that determines type of sc-element.
+        """
+        return self._impl.triples
+
+    def has_errors(self) -> bool:
+        return len(self.errors) > 0
+
+    def has_warnings(self) -> bool:
+        return len(self.warnings)
+
+    def parse(self, data: str) -> bool:
+        """Runs SCs-text parsing from string `data`.
+
+        If there were any errors during parser, then returns `False`. `errors`
+        list will contain all errors occured during parsing.
+        """
+        return self._parseImpl(antlr4.InputStream(data))
+
+    def parseFile(self, file_path: str) -> bool:
+        """Runs SCs-test parsing from file
+
+        If there were any errors during parser, then returns `False`. `errors`
+        list will contain all errors occured during parsing.
+        """
+        return self._parseImpl(antlr4.FileStream(file_path, encoding='utf-8'))
+
+    def _parseImpl(self, stream: antlr4.InputStream) -> bool:
+
+        lexer = SCsLexerAntlr(input=stream)
+        lexer.addErrorListener(self._error_listener)
+        lexer.removeErrorListener(ConsoleErrorListener.INSTANCE)
+
+        stream = antlr4.CommonTokenStream(lexer=lexer)
+        parser = SCsParserAntlr(input=stream)
+
+        parser._impl = self._impl
+        parser._errHandler = BailErrorStrategy()
+        parser.addErrorListener(self._error_listener)
+        # do not print errors to console
+        parser.removeErrorListener(ConsoleErrorListener.INSTANCE)
+
+        try:
+            parser.syntax()
+        except ParseCancellationException as ex:
+            if len(self._error_listener.errors) + len(self._impl.errors) == 0:
+                self._errors.append(ParseIssue(
+                    0, 0, '', "Wasn't able to parse input", ParseIssue.Type.ERROR))
+
+        self._errors.extend(self._error_listener.errors)
+        self._errors.extend(self._impl.errors)
+
+        self._warnings.extend(self._impl.warnings)
+
+        return len(self.errors) == 0
diff --git a/db/sc/scs/parser_impl.py b/db/sc/scs/parser_impl.py
new file mode 100644
index 0000000..63169b7
--- /dev/null
+++ b/db/sc/scs/parser_impl.py
@@ -0,0 +1,156 @@
+from sc.core.keynodes import KeynodeNames
+
+from typing import Dict, List, Set, Tuple, Union
+
+from .parse_issue import ParseIssue
+from .types import Alias, Arc, Edge, Element, Link, Node, TokenContext
+
+from antlr4.error.Errors import ParseCancellationException
+
+
+Triple = Tuple[Element, Union[Arc, Edge], Element]
+
+
+class SCsParserImpl:
+
+    def __init__(self) -> None:
+        # list of parsed triples
+        self._triples = []
+
+        # Dictionary of element types.
+        # They should be in format: {element.name, set(str)}
+        self._types = {}
+
+        # Counter for generated names
+        self._names_counter = 0
+
+        # Dictionary of alias definitions <str, AliasDefinition>
+        self._aliases = {}
+
+        # List of warnings
+        self._errors = []
+        self._warnings = []
+
+        # Stack of contours
+        self._contour_stack = []
+
+    @property
+    def errors(self) -> List[ParseIssue]:
+        return self._errors
+
+    @property
+    def warnings(self) -> List[ParseIssue]:
+        return self._warnings
+
+    @property
+    def types(self) -> Dict[str, Set[str]]:
+        """Returns dictionary with element types"""
+        return self._types
+
+    @property
+    def triples(self) -> List[Triple]:
+        """Returns list of triples"""
+        return self._triples
+
+    def _process_name(self, name: str, prefix: str = "el", force_var: bool = False) -> str:
+        def next_id():
+            self._names_counter += 1
+            return self._names_counter
+
+        if name is None or name == "..." or name == "{":
+            name = f"..{'_' if force_var else ''}{prefix}_generated_{next_id()}"
+
+        return name
+
+    def _is_type_keynode(self, name: str) -> bool:
+        """Checks if specified name if a type keynode"""
+        return name in self._type_keynodes
+
+    def _break_parsing(self, msg: str):
+        """Raises error to break parsing"""
+        raise ParseCancellationException(msg)
+
+    def create_alias(self, ctx: TokenContext) -> Alias:
+        return Alias(ctx.text, ctx, None)
+
+    def create_node(self, ctx: TokenContext) -> Node:
+        return Node(self._process_name(ctx.text, prefix="node"), ctx)
+
+    def create_link(self, ctx: TokenContext, value: Link.Value, type: Link.Type, is_var: bool) -> Link:
+        return Link(self._process_name(None, prefix="link", force_var=is_var),
+                    self._link_remove_escape_symbols(value),
+                    type, ctx)
+
+    def create_edge(self, ctx: TokenContext, connector: str) -> Edge:
+        return Edge(connector, self._process_name(None, prefix="edge"), ctx)
+
+    def create_arc(self, ctx: TokenContext, connector: str) -> Arc:
+        return Arc(connector, self._process_name(None, prefix="arc"), ctx)
+
+    def append_triple(self, src: Element, edge: Union[Edge, Arc], trg: Element):
+        def _resolve_alias(alias: Alias) -> Element:
+            try:
+                return self._aliases[alias.name].target
+            except KeyError:
+                self._new_error(alias.ctx,
+                                f"Alias {alias.name} is not defined")
+                self._break_parsing(f"Alias {alias.name} is not defined")
+
+        if src.kind == Element.Kind.ALIAS:
+            src = _resolve_alias(src)
+        if trg.kind == Element.Kind.ALIAS:
+            trg = _resolve_alias(trg)
+
+        triples = self._contour_stack[-1] if len(self._contour_stack) > 0 else self._triples
+
+        if edge._reverse_if_back():
+            triples.append((trg, edge, src))
+        else:
+            triples.append((src, edge, trg))
+
+    def define_alias(self, alias: Alias, target: Element) -> Alias:
+        """Create new alias to specified element"""
+        assert alias.target is None
+        try:
+            prev_alias = self._aliases[alias.name]
+            self._new_warning(alias.ctx,
+                              (f"Alias {alias.name} was previously defined at line: {prev_alias.ctx.line}"
+                               " column: {prev_alias.ctx.column}"))
+        except KeyError:
+            pass
+
+        new_alias = Alias(alias.name, alias.ctx, target)
+        self._aliases[new_alias.name] = new_alias
+        return new_alias
+
+    def _new_error(self, ctx: TokenContext, msg: str):
+        self._errors.append(
+            ParseIssue(ctx.line, ctx.column, ctx.text, msg, ParseIssue.Type.ERROR))
+
+    def _new_warning(self, ctx: TokenContext, msg: str):
+        self._warnings.append(
+            ParseIssue(ctx.line, ctx.column, ctx.text, msg, ParseIssue.Type.ERROR))
+
+    def _link_remove_escape_symbols(self, input: str) -> str:
+        return input.replace("\\[", "[").replace("\\]", "]").replace("\\\\", "\\")
+
+    def start_contour(self):
+        self._contour_stack.append([])
+
+    def end_contour(self, contour: Node):
+        contour_triples = self._contour_stack.pop()
+        self._triples.extend(contour_triples)
+
+        # append elements into contour
+        added = set()
+
+        def add_element(child: Element):
+            if child.name not in added:
+                edge = self.create_arc(TokenContext(-1, -1, "->"), "->")
+                self._triples.append((contour, edge, child))
+                added.add(child.name)
+
+        for src, edge, trg in contour_triples:
+            add_element(src)
+            add_element(edge)
+            add_element(trg)
diff --git a/db/sc/scs/scs.g4 b/db/sc/scs/scs.g4
new file mode 100644
index 0000000..bea5b94
--- /dev/null
+++ b/db/sc/scs/scs.g4
@@ -0,0 +1,262 @@
+grammar scs;
+
+options {
+	language = Python3;
+}
+
+@parser::header {
+from sc.scs.types import *
+from enum import Enum
+
+def create_token_context(ctx: any) -> TokenContext:
+	return TokenContext(line=ctx.line, column=ctx.column, text=ctx.text)
+
+class ConnectorType:
+	ARC = 0
+	EDGE = 1
+}
+
+content
+	returns[Element el]: (v='_')? CONTENT_BODY {
+token_context = create_token_context($CONTENT_BODY)
+$ctx.el = self._impl.create_link(token_context, $CONTENT_BODY.text[1:-1], Link.Type.STRING, $v is not None)
+};
+
+contour returns[Element el]
+	@init {count = 1}:
+	CONTOUR_BEGIN {count > 0}? {self._impl.start_contour()} (sentence_wrap*) CONTOUR_END {
+count -= 1
+if count == 0:
+	contour = self._impl.create_node(create_token_context($CONTOUR_BEGIN))
+	self._impl.end_contour(contour)
+	$ctx.el = contour
+};
+
+connector_edge
+	returns[Element el]:
+	symbol = (
+		'<>'
+		| '<=>'
+		| '_<>'
+		| '_<=>'
+		| '>'
+		| '<'
+		| '=>'
+		| '<='
+		| '_=>'
+		| '_<='
+	) {$ctx.el = self._impl.create_edge(create_token_context($symbol), $symbol.text)};
+
+connector_arc
+	returns[Element el]:
+	symbol = (
+		'..>'
+		| '<..'
+		| '->'
+		| '<-'
+		| '-|>'
+		| '<|-'
+		| '-/>'
+		| '</-'
+		| '~>'
+		| '<~'
+		| '~|>'
+		| '<|~'
+		| '~/>'
+		| '</~'
+		| '_..>'
+		| '_<..'
+		| '_->'
+		| '_<-'
+		| '_-|>'
+		| '_<|-'
+		| '_-/>'
+		| '_</-'
+		| '_~>'
+		| '_<~'
+		| '_~|>'
+		| '_<|~'
+		| '_~/>'
+		| '_</~'
+	) {$ctx.el = self._impl.create_arc(create_token_context($symbol), $symbol.text)};
+
+connector
+	returns[Element el]:
+	connector_edge {$ctx.el = $connector_edge.el}
+	| connector_arc {$ctx.el = $connector_arc.el};
+
+// ------------- Rules --------------------
+
+syntax: sentence_wrap* EOF;
+
+sentence_wrap: (sentence SENTENCE_SEP);
+
+sentence: sentence_assign | sentence_lvl_common;
+
+ifdf_alias
+	returns[Element el]:
+	ALIAS_SYMBOLS {
+$ctx.el = self._impl.create_alias(create_token_context($ALIAS_SYMBOLS))
+};
+
+idtf_system
+	returns[Element el]:
+	value = (ID_SYSTEM | '...') {
+$ctx.el = self._impl.create_node(create_token_context($value))
+};
+
+sentence_assign:
+	ALIAS_SYMBOLS '=' idtf_common {
+
+context = create_token_context($ALIAS_SYMBOLS)
+self._impl.define_alias(self._impl.create_alias(context), $idtf_common.el)
+};
+
+idtf_edge
+	returns[Elemen el]:
+	'(' src = idtf_atomic connector attr = attr_list? trg = idtf_atomic ')' {
+self._impl.append_triple($src.el, $connector.el, $trg.el)
+$ctx.el = $connector.el
+
+if $ctx.attr is not None:
+	for a, e in $attr.items:
+		self._impl.append_triple(a, e, $connector.el)
+};
+
+idtf_set_item[Element set]:
+	attr = attr_list? idtf = idtf_common {
+edge = self._impl.create_arc($idtf.el.ctx.clone(), '->')
+self._impl.append_triple($set, edge, $idtf.el)
+if $ctx.attr is not None:
+	for a, e in $attr.items:
+		self._impl.append_triple(a, e, edge)
+};
+
+idtf_set_item_list[Element set]:
+	idtf_set_item[set] (';' idtf_set_item[set])*;
+
+idtf_set
+	returns[Element el]:
+	t = '{' {
+context = create_token_context($t)
+$ctx.el = self._impl.create_node(context)
+	} idtf_set_item_list[$ctx.el] '}';
+
+idtf_atomic
+	returns[Element el]:
+	ifdf_alias {$ctx.el = $ifdf_alias.el}
+	| idtf_system {$ctx.el = $idtf_system.el};
+
+idtf_url
+	returns[Element el]:
+	LINK {
+context = create_token_context($LINK)
+$ctx.el = self._impl.create_link(context, $LINK.text[1:-1], Link.Type.URL, False)
+};
+
+idtf_common
+	returns[Element el]:
+	idtf_atomic {$ctx.el = $idtf_atomic.el}
+	| idtf_edge {$ctx.el = $idtf_edge.el}
+	| idtf_set {$ctx.el = $idtf_set.el}
+	| contour {$ctx.el = $contour.el}
+	| content {$ctx.el = $content.el}
+	| idtf_url {$ctx.el = $idtf_url.el};
+
+idtf_list
+	returns[items]
+	@init {$ctx.items = []}:
+	first = idtf_common {$ctx.items.append($first.el)} internal_sentence_list[$first.el]? (
+		';' second = idtf_common {$ctx.items.append($second.el)} internal_sentence_list[$first.el]?
+	)*;
+
+internal_sentence[Element src]:
+	c = connector attr = attr_list? target = idtf_list {
+
+for t in $target.items:
+	edge = None
+	if isinstance($c.el, Edge):
+		edge = self._impl.create_edge($c.el.ctx, $c.el.connector)
+	else:
+		edge = self._impl.create_arc($c.el.ctx, $c.el.connector)
+	self._impl.append_triple($src, edge, t)
+	if $ctx.attr is not None:
+		for a, e in $attr.items:
+			self._impl.append_triple(a, e, edge)
+
+};
+
+internal_sentence_list[Element src]:
+	'(*' (internal_sentence[src] SENTENCE_SEP)+ '*)';
+
+sentence_lvl_4_list_item[Element src]:
+	(c = connector attr = attr_list? target = idtf_list) {
+for t in $target.items:
+	edge = None
+	if isinstance($c.el, Edge):
+		edge = self._impl.create_edge($c.el.ctx, $c.el.connector)
+	else:
+		edge = self._impl.create_arc($c.el.ctx, $c.el.connector)
+
+	self._impl.append_triple($src, edge, t)
+	if $ctx.attr is not None:
+		for a, e in $attr.items:
+			self._impl.append_triple(a, e, edge)
+};
+
+sentence_lvl_common:
+	idtf_common sentence_lvl_4_list_item[$idtf_common.el] (
+		';' sentence_lvl_4_list_item[$idtf_common.el]
+	)*;
+
+attr_list
+	returns[items]
+	@init {$ctx.items = []}: (
+		ID_SYSTEM EDGE_ATTR {
+node = self._impl.create_node(create_token_context($ID_SYSTEM))
+edge = None
+connector = "->" if $EDGE_ATTR.text == ":" else "_->"
+edge = self._impl.create_arc(create_token_context($EDGE_ATTR), connector)
+
+$ctx.items.append((node, edge))
+}
+	)+;
+
+// ----------------------------
+
+ID_SYSTEM: ('a' ..'z' | 'A' ..'Z' | '_' | '.' | '0' ..'9')+;
+
+ALIAS_SYMBOLS:
+	'@' ('a' ..'z' | 'A' ..'Z' | '_' | '0' ..'9')+;
+
+fragment CONTENT_ESCAPED: '\\' ('[' | ']' | '\\');
+
+fragment CONTENT_SYBMOL: (CONTENT_ESCAPED | ~('[' | ']' | '\\'));
+
+fragment CONTENT_SYBMOL_FIRST_END: (
+		CONTENT_ESCAPED
+		| ~('[' | ']' | '\\' | '*')
+	);
+
+CONTOUR_BEGIN: '[*';
+
+CONTOUR_END: '*]';
+
+CONTENT_BODY:
+	'[]'
+	| '[' CONTENT_SYBMOL_FIRST_END CONTENT_SYBMOL* ']';
+
+LINK: '"' (~('"') | '\\"')* '"';
+
+EDGE_ATTR: ':' | '::';
+
+LINE_TERMINATOR: [\r\n\u2028\u2029] -> channel(HIDDEN);
+
+LINE_COMMENT:
+	'//' ~('\n' | '\r')* '\r'? '\n' -> channel(HIDDEN);
+
+MULTINE_COMMENT: '/*' .*? '*/' -> channel(HIDDEN);
+
+WS: ( ' ' | '\t' | '\r' | '\n') -> channel(HIDDEN);
+
+SENTENCE_SEP: ';;';
diff --git a/db/sc/scs/types.py b/db/sc/scs/types.py
new file mode 100644
index 0000000..2cb390d
--- /dev/null
+++ b/db/sc/scs/types.py
@@ -0,0 +1,156 @@
+from enum import Enum
+from sys import is_finalizing
+from typing import Union
+
+import re
+
+
+class TokenContext:
+
+    def __init__(self, line: int, column: int, text: str) -> None:
+        self.line = line
+        self.column = column
+        self.text = text
+
+    def __repr__(self) -> str:
+        return f"{{ line: {self.line}, column: {self.column}, text: `{self.text}`}}"
+
+    def clone(self):
+        return TokenContext(self.line, self.column, self.text)
+
+
+class Element:
+
+    class Kind(Enum):
+        ALIAS = 0
+        NODE = 1
+        EDGE = 2
+        ARC = 3
+        LINK = 4
+
+    def __init__(self, kind: Kind, name: str, ctx: TokenContext) -> None:
+        self.kind = kind
+        self.name = name
+        self.ctx = ctx
+
+    def is_const(self) -> bool:
+        return not self.is_var()
+
+    def is_var(self) -> bool:
+        return re.fullmatch(re.compile("^\.{0,2}_.*$"), self.name) is not None
+
+    def __repr__(self) -> str:
+        return self._to_str()
+
+    def _to_str(self, **kwargs):
+        attrs = ', '.join([f"{k}: {v}" for k, v in kwargs.items()])
+        return(
+            f"{self.__class__.__name__}(ctx: {self.ctx}, "
+            f"kind: {self.kind.name}, "
+            f"name: {self.name}"
+            f"{', ' + attrs if len(attrs) > 0 else ''})")
+
+
+class Alias(Element):
+
+    def __init__(self, name: str, ctx: TokenContext, target: Element) -> None:
+        super().__init__(Element.Kind.ALIAS, name, ctx)
+
+        self.target = target
+
+    def __repr__(self) -> str:
+        return self._to_str(target=self.target)
+
+
+class Node(Element):
+
+    def __init__(self, name: str, ctx: TokenContext) -> None:
+        super().__init__(Element.Kind.NODE, name, ctx)
+
+
+class Edge(Element):
+
+    VALID = {'<>', '<=>', '_<>', '_<=>', '>',
+             '<', '=>', '<=', '_=>', '_<='}
+    BACKWARD = {'<', '<=', '_<='}
+    REVERSE_DICT = {
+        '<': '>',
+        '<=': '=>',
+        '_<=': '_=>'
+    }
+
+    def __init__(self, connector: str, name: str, ctx: TokenContext) -> None:
+        super().__init__(Element.Kind.EDGE, name, ctx)
+
+        self.connector = connector
+        if self.connector not in Edge.VALID:
+            raise KeyError(
+                f"Connector `{connector}` is not supported. List of supported connectors: {Edge.VALID}")
+
+    def _reverse_if_back(self) -> bool:
+        """Reverse connector to forward direction.
+
+        If connector was reversed, then returns True.
+        """
+        if self.connector in Edge.BACKWARD:
+            self.connector = Edge.REVERSE_DICT[self.connector]
+            return True
+
+        return False
+
+    def __repr__(self) -> str:
+        return self._to_str(connector=self.connector)
+
+
+class Arc(Element):
+
+    VALID = {'..>', '<..', '->', '<-', '-|>', '<|-', '-/>', '</-', '~>', '<~', '~|>', '<|~', '~/>', '</~',
+             '_..>', '_<..', '_->', '_<-', '_-|>', '_<|-', '_-/>', '_</-', '_~>', '_<~', '_~|>', '_<|~', '_~/>', '_</~'}
+    BACKWARD = {'<..', '<-', '<|-', '</-', '<~', '<|~',  '</~',
+                '_<..',  '_<-', '_<|-', '_</-',  '_<~',  '_<|~', '_</~'}
+    REVERSE_DICT = {
+        '<..': '..>',
+        '<-': '->', '<|-': '-|>', '</-': '-/>', '<~': '~>', '<|~': "~|>",  '</~': '~/>',
+        '_<..': '_..>',  '_<-': '_->', '_<|-': '_-|>', '_</-': '_-/>',  '_<~': '_~>',  '_<|~': '_~|>', '_</~': '_~/>'
+    }
+
+    def __init__(self, connector: str, name: str, ctx: TokenContext) -> None:
+        super().__init__(Element.Kind.ARC, name, ctx)
+
+        self.connector = connector
+
+        if self.connector not in Arc.VALID:
+            raise KeyError(
+                f"Connector `{connector}` is not supported. List of supported connectors: {Arc.VALID}")
+
+    def _reverse_if_back(self) -> bool:
+        """Reverse connector to forward direction.
+
+        If connector was reversed, then returns True.
+        """
+        if self.connector in Arc.BACKWARD:
+            self.connector = Arc.REVERSE_DICT[self.connector]
+            return True
+
+        return False
+
+    def __repr__(self) -> str:
+        return self._to_str(connector=self.connector)
+
+
+class Link(Element):
+
+    Value = Union[str, int, float]
+
+    class Type(Enum):
+        STRING = 0
+        URL = 1
+
+    def __init__(self, name: str, value: Value, type_: Type, ctx: TokenContext) -> None:
+        super().__init__(Element.Kind.LINK, name, ctx)
+
+        self.value = value
+        self.type = type_
+
+    def __repr__(self) -> str:
+        return self._to_str(value=self.value, type=self.type.name)
diff --git a/db/scripts/generate_antlr.sh b/db/scripts/generate_antlr.sh
new file mode 100755
index 0000000..f9a0748
--- /dev/null
+++ b/db/scripts/generate_antlr.sh
@@ -0,0 +1,6 @@
+if [ -z "$1" ]
+then
+      echo "Please specify path to antlr tool. For example:\033[1;34m generate_antlr.sh antlr-4.9.2-complete.jar\033[0m"
+else
+      java -jar $1 -Dlanguage=Python3 -o sc/scs/antlr -no-listener -no-visitor -Xexact-output-dir sc/scs/scs.g4
+fi
\ No newline at end of file
diff --git a/db/tests/units/scs/__init__.py b/db/tests/units/scs/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/db/tests/units/scs/test_scs_alias.py b/db/tests/units/scs/test_scs_alias.py
new file mode 100644
index 0000000..13f2738
--- /dev/null
+++ b/db/tests/units/scs/test_scs_alias.py
@@ -0,0 +1,81 @@
+import unittest
+
+from sc.scs.parser import SCsParser
+from sc.scs.types import *
+
+
+class TestSCsAlias(unittest.TestCase):
+
+    def test_edge_smoke(self):
+        parser = SCsParser()
+
+        self.assertTrue(parser.parse("@alias = (x -> y);;"))
+        self.assertEqual(len(parser.triples), 1)
+
+    def test_contour_smoke(self):
+        parser = SCsParser()
+
+        self.assertTrue(parser.parse(
+            ("@alias = _[];;"
+             "x -> [* @alias2 = y;;"
+             "       @alias _~> @alias2;;"
+             "*];;")))
+
+        self.assertEqual(len(parser.triples), 5)
+
+    def test_usage(self):
+        parser = SCsParser()
+
+        self.assertTrue(parser.parse("@alias = [];; x ~> @alias;;"))
+        self.assertEqual(len(parser.triples), 1)
+        self.assertFalse(parser.has_warnings())
+
+        src, _, trg = parser.triples[0]
+
+        self.assertIsInstance(src, Node)
+        self.assertIsInstance(trg, Link)
+
+    def test_not_defined(self):
+        parser = SCsParser()
+
+        self.assertFalse(parser.parse("x -> @alias;;"))
+        self.assertEqual(len(parser.errors), 1)
+        self.assertFalse(parser.has_warnings())
+
+    def test_reassign_warning(self):
+        parser = SCsParser()
+
+        self.assertTrue(parser.parse(
+            ("@alias = (x -> y);;"
+             "@alias = (z -> y);;")))
+        self.assertEqual(len(parser.triples), 2)
+        self.assertEqual(len(parser.warnings), 1)
+
+    def test_reassign(self):
+        parser = SCsParser()
+
+        self.assertTrue(parser.parse(
+            ("@alias = x;;"
+             "y -> @alias;;"
+             "@alias = z;;"
+             "@alias -> c;;")))
+
+        self.assertEqual(len(parser.triples), 2)
+
+        src, _, _ = parser.triples[1]
+        self.assertEqual(src.name, "z")
+
+    def test_assign_alias_to_alias(self):
+        parser = SCsParser()
+
+        self.assertTrue(parser.parse(
+            ("@alias1 = x;;"
+             "@alias1 <- sc_node_tuple;;"
+             "@alias2 = @alias1;;"
+             "_y -|> @alias2;;")))
+
+        self.assertEqual(len(parser.triples), 2)
+        self.assertFalse(parser.has_warnings())
+
+        _, _, trg = parser.triples[0]
+        self.assertEqual(trg.name, "x")
diff --git a/db/tests/units/scs/test_scs_level2.py b/db/tests/units/scs/test_scs_level2.py
new file mode 100644
index 0000000..68e0a34
--- /dev/null
+++ b/db/tests/units/scs/test_scs_level2.py
@@ -0,0 +1,85 @@
+import unittest
+
+from sc.scs.types import *
+from sc.scs.parser import SCsParser
+
+
+class TestSCsLevel2(unittest.TestCase):
+
+    def test_reverse(self):
+        parser = SCsParser()
+
+        self.assertTrue(parser.parse("b <- a;;"))
+        self.assertEqual(len(parser.triples), 1)
+
+        src, edge, trg = parser.triples[0]
+        self.assertEqual(src.name, "a")
+        self.assertEqual(edge.connector, "->")
+        self.assertEqual(trg.name, "b")
+
+    def test_smoke(self):
+        parser = SCsParser()
+
+        self.assertTrue(parser.parse("a -> (b <- c);;"))
+        self.assertEqual(len(parser.triples), 2)
+
+        src, edge, trg = parser.triples[0]
+        self.assertEqual(src.name, "c")
+        self.assertEqual(edge.connector, "->")
+        self.assertEqual(trg.name, "b")
+
+        src, edge, trg = parser.triples[1]
+        self.assertEqual(src.name, "a")
+        self.assertEqual(edge.connector, "->")
+        self.assertIsInstance(trg, Arc)
+
+    def test_smoke_2(self):
+        parser = SCsParser()
+
+        self.assertTrue(parser.parse("(c <- x) <- (b <> y);;"))
+        self.assertEqual(len(parser.triples), 3)
+
+        src, edge, trg = parser.triples[0]
+        self.assertIsInstance(src, Node)
+        self.assertEqual(src.name, "x")
+        self.assertIsInstance(edge, Arc)
+        self.assertEqual(edge.connector, "->")
+        self.assertIsInstance(trg, Node)
+        self.assertEqual(trg.name, "c")
+
+        src, edge, trg = parser.triples[1]
+        self.assertIsInstance(src, Node)
+        self.assertEqual(src.name, "b")
+        self.assertIsInstance(edge, Edge)
+        self.assertEqual(edge.connector, "<>")
+        self.assertIsInstance(trg, Node)
+        self.assertEqual(trg.name, "y")
+
+        src, edge, trg = parser.triples[2]
+        self.assertIsInstance(src, Edge)
+        self.assertIsInstance(edge, Arc)
+        self.assertEqual(edge.connector, "->")
+        self.assertIsInstance(trg, Arc)
+
+    def test_unnamed(self):
+        parser = SCsParser()
+
+        self.assertTrue(parser.parse("a -> ...; -> ...;;"))
+        self.assertEqual(len(parser.triples), 2)
+
+        _, _, trg = parser.triples[0]
+        self.assertIsInstance(trg, Node)
+
+        _, _, trg = parser.triples[1]
+        self.assertIsInstance(trg, Node)
+
+    def test_invalid(self):
+        tests = ["a -> (x -> (y -> z));;",
+                 "a -> (x -> [content]);;",
+                 "a -> (x -> [* y -> z ;; *]);;",
+                 "a -> (x -> { y; z });;"]
+
+        for t in tests:
+            parser = SCsParser()
+            self.assertFalse(parser.parse(t))
+            self.assertGreater(len(parser.errors), 0)
diff --git a/db/tests/units/scs/test_scs_level3.py b/db/tests/units/scs/test_scs_level3.py
new file mode 100644
index 0000000..e2496f9
--- /dev/null
+++ b/db/tests/units/scs/test_scs_level3.py
@@ -0,0 +1,61 @@
+import unittest
+
+from sc.scs.types import *
+from sc.scs.parser import SCsParser
+
+
+class TestSCsLevel3(unittest.TestCase):
+
+    def test_smoke(self):
+        parser = SCsParser()
+
+        self.assertTrue(parser.parse("a -> c: _b:: d;;"))
+        self.assertEqual(len(parser.triples), 3)
+
+        src, edge, trg = parser.triples[0]
+        self.assertEqual(src.name, "a")
+        self.assertEqual(edge.connector, "->")
+        self.assertEqual(trg.name, "d")
+
+        src, edge, trg = parser.triples[1]
+        self.assertEqual(src.name, "c")
+        self.assertEqual(edge.connector, "->")
+        self.assertIsInstance(trg, Arc)
+
+        src, edge, trg = parser.triples[2]
+        self.assertEqual(src.name, "_b")
+        self.assertEqual(edge.connector, "_->")
+        self.assertIsInstance(trg, Arc)
+
+    def test_complex(self):
+        parser = SCsParser()
+
+        self.assertTrue(parser.parse("(a _<- f: d) -/> (c ~> b:: d);;"))
+        self.assertEqual(len(parser.triples), 5)
+
+        src, edge, trg = parser.triples[0]
+        self.assertEqual(src.name, "d")
+        self.assertEqual(edge.connector, "_->")
+        self.assertEqual(trg.name, "a")
+
+        src, edge, trg = parser.triples[1]
+        self.assertEqual(src.name, "f")
+        self.assertEqual(edge.connector, "->")
+        self.assertIsInstance(trg, Arc)
+        self.assertEqual(trg.connector, "_->")
+
+        src, edge, trg = parser.triples[2]
+        self.assertEqual(src.name, "c")
+        self.assertEqual(edge.connector, "~>")
+        self.assertEqual(trg.name, "d")
+
+        src, edge, trg = parser.triples[3]
+        self.assertEqual(src.name, "b")
+        self.assertEqual(edge.connector, "_->")
+        self.assertIsInstance(trg, Arc)
+        self.assertEqual(trg.connector, "~>")
+
+        src, edge, trg = parser.triples[4]
+        self.assertIsInstance(src, Arc)
+        self.assertEqual(edge.connector, "-/>")
+        self.assertIsInstance(trg, Arc)
diff --git a/db/tests/units/scs/test_scs_level4.py b/db/tests/units/scs/test_scs_level4.py
new file mode 100644
index 0000000..4f4d545
--- /dev/null
+++ b/db/tests/units/scs/test_scs_level4.py
@@ -0,0 +1,55 @@
+import unittest
+
+from sc.scs.parser import SCsParser
+from sc.scs.types import *
+
+
+class TestSCsLevel4(unittest.TestCase):
+
+    def test_smoke(self):
+        parser = SCsParser()
+
+        self.assertTrue(parser.parse("a -> b: c; d;;"))
+        self.assertEqual(len(parser.triples), 4)
+
+        src, _, trg = parser.triples[0]
+        self.assertEqual(src.name, "a")
+        self.assertEqual(trg.name, "c")
+
+        src, _, trg = parser.triples[1]
+        self.assertEqual(src.name, "b")
+        self.assertIsInstance(trg, Arc)
+
+        src, _, trg = parser.triples[2]
+        self.assertEqual(src.name, "a")
+        self.assertEqual(trg.name, "d")
+
+        src, _, trg = parser.triples[3]
+        self.assertEqual(src.name, "b")
+        self.assertIsInstance(trg, Arc)
+
+    def test_complex(self):
+        parser = SCsParser()
+
+        self.assertTrue(parser.parse("a -> b: c; <- d: e: f;;"))
+        self.assertEqual(len(parser.triples), 5)
+
+        src, _, trg = parser.triples[0]
+        self.assertEqual(src.name, "a")
+        self.assertEqual(trg.name, "c")
+
+        src, _, trg = parser.triples[1]
+        self.assertEqual(src.name, "b")
+        self.assertIsInstance(trg, Arc)
+
+        src, _, trg = parser.triples[2]
+        self.assertEqual(src.name, "f")
+        self.assertEqual(trg.name, "a")
+
+        src, _, trg = parser.triples[3]
+        self.assertEqual(src.name, "d")
+        self.assertIsInstance(trg, Arc)
+
+        src, _, trg = parser.triples[4]
+        self.assertEqual(src.name, "e")
+        self.assertIsInstance(trg, Arc)
diff --git a/db/tests/units/scs/test_scs_level5.py b/db/tests/units/scs/test_scs_level5.py
new file mode 100644
index 0000000..d5a5e1c
--- /dev/null
+++ b/db/tests/units/scs/test_scs_level5.py
@@ -0,0 +1,37 @@
+import unittest
+
+from sc.scs.parser import SCsParser
+from sc.scs.types import *
+
+
+class TestSCsLevel5(unittest.TestCase):
+
+    def test_smoke(self):
+        parser = SCsParser()
+
+        self.assertTrue(parser.parse((
+            "set ~> attr:: item"
+            "  (* -/> subitem;;"
+            "     <= subitem2;; *);;")))
+
+        self.assertEqual(len(parser.triples), 4)
+
+        src, edge, trg = parser.triples[0]
+        self.assertEqual(src.name, "item")
+        self.assertEqual(edge.connector, "-/>")
+        self.assertEqual(trg.name, "subitem")
+
+        src, edge, trg = parser.triples[1]
+        self.assertEqual(src.name, "subitem2")
+        self.assertEqual(edge.connector, "=>")
+        self.assertEqual(trg.name, "item")
+
+        src, edge, trg = parser.triples[2]
+        self.assertEqual(src.name, "set")
+        self.assertIsInstance(edge, Arc)
+        self.assertEqual(trg.name, "item")
+
+        src, edge, trg = parser.triples[3]
+        self.assertEqual(src.name, "attr")
+        self.assertEqual(edge.connector, "_->")
+        self.assertIsInstance(trg, Arc)
diff --git a/db/tests/units/scs/test_scs_level6.py b/db/tests/units/scs/test_scs_level6.py
new file mode 100644
index 0000000..6da92af
--- /dev/null
+++ b/db/tests/units/scs/test_scs_level6.py
@@ -0,0 +1,235 @@
+from ast import parse
+import unittest
+
+from sc.scs.parser import SCsParser
+from sc.scs.types import *
+
+
+class TestSCsLevel6(unittest.TestCase):
+
+    def test_smoke(self):
+        tests = ["z -> [**];;",
+                 "x -> [test*];;",
+                 "@a = [\\[* r-> b;; *\\]];;",
+                 "@alias = u;; @alias -> [* x -> [* y -> z;; *];; *];;",
+                 "y <= nrel_main_idtf: [y*];;",
+                 "a -> [* z -> [begin*];; *];;",
+                 "a -> [* b -> c;; *];;"]
+        for t in tests:
+            parser = SCsParser()
+            self.assertTrue(parser.parse(t))
+
+    def test_set(self):
+        parser = SCsParser()
+
+        self.assertTrue(parser.parse("@set = { a; b: c; d: e: f };;"))
+        self.assertEqual(len(parser.triples), 6)
+
+        common_src = parser.triples[0][0]
+
+        src, edge, trg = parser.triples[0]
+        self.assertIsInstance(src, Node)
+        self.assertEqual(edge.connector, "->")
+        self.assertEqual(trg.name, "a")
+
+        src, edge, trg = parser.triples[1]
+        self.assertIsInstance(src, Node)
+        self.assertEqual(src.name, common_src.name)
+        self.assertEqual(edge.connector, "->")
+        self.assertEqual(trg.name, "c")
+
+        src, edge, trg = parser.triples[2]
+        self.assertEqual(src.name, "b")
+        self.assertEqual(edge.connector, "->")
+        self.assertIsInstance(trg, Arc)
+
+        src, edge, trg = parser.triples[3]
+        self.assertIsInstance(src, Node)
+        self.assertEqual(src.name, common_src.name)
+        self.assertEqual(edge.connector, "->")
+        self.assertEqual(trg.name, "f")
+
+        src, edge, trg = parser.triples[4]
+        self.assertEqual(src.name, "d")
+        self.assertEqual(edge.connector, "->")
+        self.assertIsInstance(trg, Arc)
+
+        src, edge, trg = parser.triples[5]
+        self.assertEqual(src.name, "e")
+        self.assertEqual(edge.connector, "->")
+        self.assertIsInstance(trg, Arc)
+
+    def test_set_recursive(self):
+        parser = SCsParser()
+
+        self.assertTrue(parser.parse("@set = { a; {b} };;"))
+        self.assertEqual(len(parser.triples), 3)
+
+        src, edge, trg = parser.triples[0]
+        self.assertIsInstance(src, Node)
+        self.assertEqual(edge.connector, "->")
+        self.assertIsInstance(trg, Node)
+
+        src, edge, trg = parser.triples[1]
+        self.assertIsInstance(src, Node)
+        self.assertEqual(edge.connector, "->")
+        self.assertEqual(trg.name, "b")
+
+        prev_src = src
+
+        src, edge, trg = parser.triples[2]
+        self.assertEqual(prev_src.name, trg.name)
+
+        self.assertIsInstance(src, Node)
+        self.assertEqual(edge.connector, "->")
+        self.assertIsInstance(trg, Node)
+
+    def test_content_empty(self):
+        parser = SCsParser()
+
+        self.assertTrue(parser.parse("a -> [];;"))
+        self.assertEqual(len(parser.triples), 1)
+
+        src, edge, trg = parser.triples[0]
+        self.assertEqual(src.name, "a")
+        self.assertEqual(edge.connector, "->")
+        self.assertIsInstance(trg, Link)
+        self.assertEqual(trg.value, "")
+        self.assertTrue(trg.is_const())
+
+    def test_content_simple(self):
+        parser = SCsParser()
+
+        self.assertTrue(parser.parse("a -> [simple];;"))
+        self.assertEqual(len(parser.triples), 1)
+
+        src, edge, trg = parser.triples[0]
+        self.assertEqual(src.name, "a")
+        self.assertEqual(edge.connector, "->")
+        self.assertIsInstance(trg, Link)
+        self.assertEqual(trg.value, "simple")
+        self.assertTrue(trg.is_const())
+
+    def test_content_var(self):
+        parser = SCsParser()
+
+        self.assertTrue(parser.parse("a -> _[simple];;"))
+        self.assertEqual(len(parser.triples), 1)
+
+        src, edge, trg = parser.triples[0]
+        self.assertEqual(src.name, "a")
+        self.assertEqual(edge.connector, "->")
+        self.assertIsInstance(trg, Link)
+        self.assertEqual(trg.value, "simple")
+        self.assertTrue(trg.is_var())
+
+    def test_content_multiline(self):
+        parser = SCsParser()
+
+        self.assertTrue(parser.parse((
+            "a -> [simple\n"
+            " multiline];;")))
+        self.assertEqual(len(parser.triples), 1)
+
+        src, edge, trg = parser.triples[0]
+        self.assertEqual(src.name, "a")
+        self.assertEqual(edge.connector, "->")
+        self.assertIsInstance(trg, Link)
+        self.assertEqual(len(trg.value.split('\n')), 2)
+        self.assertTrue(trg.is_const())
+
+    def test_content_escaping(self):
+        tests = [
+            ("x -> _[\\[test\\]];;", "[test]"),
+            ("x -> _[\\\\\\[test\\\\\\]];;", "\\[test\\]")
+        ]
+
+        for input, output in tests:
+            parser = SCsParser()
+            self.assertTrue(parser.parse(input))
+            self.assertEqual(len(parser.triples), 1)
+
+            _, _, link = parser.triples[0]
+            self.assertIsInstance(link, Link)
+            self.assertEqual(link.value, output)
+
+    def test_content_error(self):
+        tests = [
+            "@alias = [;;",
+            "x -> y (* -> name: [name ;;",
+            ]
+
+        for t in tests:
+            parser = SCsParser()
+            self.assertFalse(parser.parse(t))
+            self.assertGreater(len(parser.errors), 0)
+
+    def test_contour_empty(self):
+        parser = SCsParser()
+
+        self.assertTrue(parser.parse("x -> [**];;"))
+        self.assertEqual(len(parser.triples), 1)
+
+        src, edge, trg = parser.triples[0]
+        self.assertEqual(src.name, "x")
+        self.assertEqual(edge.connector, "->")
+        self.assertIsInstance(trg, Node)
+
+    def test_contour_simple(self):
+        parser = SCsParser()
+
+        self.assertTrue(parser.parse("x -|> [* y _=> z;; *];;"))
+        self.assertEqual(len(parser.triples), 5)
+
+        src, edge, trg = parser.triples[0]
+        self.assertEqual(src.name, "y")
+        self.assertEqual(edge.connector, "_=>")
+        self.assertEqual(trg.name, "z")
+
+        _, edge, trg = parser.triples[1]
+        self.assertEqual(edge.connector, "->")
+        self.assertEqual(trg.name, "y")
+
+        _, edge, trg = parser.triples[2]
+        self.assertEqual(edge.connector, "->")
+        self.assertIsInstance(trg, Edge)
+        self.assertEqual(trg.connector, "_=>")
+
+        _, edge, trg = parser.triples[3]
+        self.assertEqual(edge.connector, "->")
+        self.assertEqual(trg.name, "z")
+
+        src, edge, trg = parser.triples[4]
+        self.assertEqual(src.name, "x")
+        self.assertEqual(edge.connector, "-|>")
+        self.assertIsInstance(trg, Node)
+
+
+    def test_countour_recursive(self):
+        parser = SCsParser()
+
+        self.assertTrue(parser.parse("x ~|> [* y _=> [* k ~> z;; *];; *];;"))
+        self.assertEqual(len(parser.triples), 9)
+
+    def test_countour_with_content(self):
+        parser = SCsParser()
+
+        self.assertTrue(parser.parse("x -> [* y _=> [test*];; *];;"))
+        self.assertEqual(len(parser.triples), 5)
+
+        _, edge, trg = parser.triples[0]
+        self.assertIsInstance(trg, Link)
+        self.assertEqual(trg.value, "test*")
+        self.assertEqual(edge.connector, "_=>")
+
+    def test_countour_error(self):
+        tests = [
+            "x -> [* y -> z *];;",
+            "y -> [* z -> [* *];;",
+            "x -> [* y -> z;; ];;",
+        ]
+
+        for t in tests:
+            parser = SCsParser()
+            self.assertFalse(parser.parse(t))
+            self.assertEqual(len(parser.errors), 1)
diff --git a/db/tests/units/scs/test_scs_link.py b/db/tests/units/scs/test_scs_link.py
new file mode 100644
index 0000000..1b054b6
--- /dev/null
+++ b/db/tests/units/scs/test_scs_link.py
@@ -0,0 +1,29 @@
+import unittest
+
+from sc.scs.parser import SCsParser
+from sc.scs.types import Arc, Edge, Element, Link, Node
+
+
+class TestSCsLink(unittest.TestCase):
+
+    def test_link_smoke(self):
+        parser = SCsParser()
+
+        self.assertTrue(parser.parse("a -> [value];;"))
+        self.assertEqual(len(parser.triples), 1)
+
+        _, _, link = parser.triples[0]
+        self.assertIsInstance(link, Link)
+        self.assertEqual(link.type, Link.Type.STRING)
+        self.assertEqual(link.value, "value")
+
+    def test_url_smoke(self):
+        parser = SCsParser()
+
+        self.assertTrue(parser.parse("a -> \"url://value\";;"))
+        self.assertEqual(len(parser.triples), 1)
+
+        _, _, link = parser.triples[0]
+        self.assertIsInstance(link, Link)
+        self.assertEqual(link.type, Link.Type.URL)
+        self.assertEqual(link.value, "url://value")
diff --git a/db/tests/units/scs/test_scs_parser.py b/db/tests/units/scs/test_scs_parser.py
new file mode 100644
index 0000000..ce2356b
--- /dev/null
+++ b/db/tests/units/scs/test_scs_parser.py
@@ -0,0 +1,43 @@
+import unittest
+
+from sc import SCsParser
+
+
+class TestSCsParser(unittest.TestCase):
+
+    def test_smoke(self):
+        parser = SCsParser()
+        self.assertTrue(parser.parse("x -> y;;"))
+
+    def test_smoke_error(self):
+        parser = SCsParser()
+        self.assertFalse(parser.parse("x -> y;"))
+        self.assertEqual(len(parser.errors), 1)
+
+    def test_comments(self):
+        parser = SCsParser()
+        self.assertTrue(parser.parse((
+            "//Level1\n"
+            "a -> b;;/* example */\n"
+            "c <> d;;"
+        )))
+        self.assertEqual(len(parser.triples), 2)
+
+    def test_links(self):
+        parser = SCsParser()
+        self.assertTrue(parser.parse((
+            "a -> \"file://data.txt\";;"
+            "b -> [x];;"
+            "c -> _[];;"
+            "d -> [];;"
+        )))
+        self.assertEqual(len(parser.triples), 4)
+
+    def test_type_no_error(self):
+        parser = SCsParser()
+        self.assertTrue(parser.parse((
+            "a <- sc_node_abstract;;"
+            "a <- sc_node_role_relation;;"
+        )))
+        self.assertFalse(parser.has_errors())
+        self.assertEqual(len(parser.triples), 2)
diff --git a/db/tests/units/scs/test_scs_types.py b/db/tests/units/scs/test_scs_types.py
new file mode 100644
index 0000000..25dda5d
--- /dev/null
+++ b/db/tests/units/scs/test_scs_types.py
@@ -0,0 +1,44 @@
+import unittest
+
+from sc.scs.types import *
+
+
+class TestSCsElement(unittest.TestCase):
+
+    def test_element_idtf(self):
+        el = Element(Element.Kind.NODE, name="_idtf", ctx=None)
+        self.assertTrue(el.is_var())
+
+        el = Element(Element.Kind.NODE, name=".._idtf", ctx=None)
+        self.assertTrue(el.is_var())
+
+        el = Element(Element.Kind.NODE, name="._idtf", ctx=None)
+        self.assertTrue(el.is_var())
+
+        el = Element(Element.Kind.NODE, name="_idtf", ctx=None)
+        self.assertTrue(el.is_var())
+
+        el = Element(Element.Kind.NODE, name="...", ctx=None)
+        self.assertTrue(el.is_const())
+
+        el = Element(Element.Kind.NODE, name="..idtf", ctx=None)
+        self.assertTrue(el.is_const())
+
+        el = Element(Element.Kind.NODE, name=".idtf", ctx=None)
+        self.assertTrue(el.is_const())
+
+    def test_arc_reverse(self):
+        arc = Arc('->', '', TokenContext(0, 0, ''))
+        self.assertFalse(arc._reverse_if_back())
+
+        arc.connector = '<-'
+        self.assertTrue(arc._reverse_if_back())
+        self.assertEqual(arc.connector, '->')
+
+    def test_edge_reverse(self):
+        edge = Edge('_=>', '', TokenContext(0, 0, ''))
+        self.assertFalse(edge._reverse_if_back())
+
+        edge.connector = '_<='
+        self.assertTrue(edge._reverse_if_back())
+        self.assertEqual(edge.connector, '_=>')
diff --git a/db/tools/bootstrap/step.py b/db/tools/bootstrap/step.py
index dfc5189..4398b54 100644
--- a/db/tools/bootstrap/step.py
+++ b/db/tools/bootstrap/step.py
@@ -2,7 +2,7 @@
 import neo4j
 
 from sc.core.keywords import Labels, TypeAttrs
-from sc.core.keynodes import Keynodes
+from sc.core.keynodes import KeynodeNames
 from sc.core.config import Config
 
 from typing import Union
@@ -31,7 +31,7 @@ def wrap_enum(e) -> object:
             return result
 
         return templ.render(
-            Keynodes=Keynodes,
+            KeynodeNames=KeynodeNames,
             Labels=Labels,
             TypeConst=wrap_enum(TypeConst),
             TypeNodeStruct=wrap_enum(TypeNodeStruct),
diff --git a/db/tools/bootstrap/steps/0001-sys_idtf.cypher.jinja b/db/tools/bootstrap/steps/0001-sys_idtf.cypher.jinja
index b7a7939..cff7aca 100644
--- a/db/tools/bootstrap/steps/0001-sys_idtf.cypher.jinja
+++ b/db/tools/bootstrap/steps/0001-sys_idtf.cypher.jinja
@@ -1,7 +1,7 @@
 {% import 'lib/types.cypher.jinja' as types with context %}
 
 CREATE 
-  (link:{{Labels.SC_LINK}} {content: "{{Keynodes.NREL_SYS_IDTF}}", is_url: false, type: "str", {{ types.const_attr(TypeConst.CONST) }} }),
+  (link:{{Labels.SC_LINK}} {content: "{{KeynodeNames.NREL_SYS_IDTF}}", is_url: false, type: "str", {{ types.const_attr(TypeConst.CONST) }} }),
   (node:{{Labels.SC_NODE}} { {{ types.node_const_no_role_attrs() }} }),
   (node)-[edge:{{Labels.SC_ARC}} { {{ types.const_attr(TypeConst.CONST) }} }]->(link)
 WITH edge, node
diff --git a/db/tools/bootstrap/steps/0010-types.cypher.jinja b/db/tools/bootstrap/steps/0010-types.cypher.jinja
index 8f99858..ecc79da 100644
--- a/db/tools/bootstrap/steps/0010-types.cypher.jinja
+++ b/db/tools/bootstrap/steps/0010-types.cypher.jinja
@@ -1,13 +1,11 @@
 {% import 'lib/names.cypher.jinja' as names with context %}
 {% import 'lib/types.cypher.jinja' as types with context %}
 
-{% set keynodes_list = [
-  'sc_node', 'sc_link', 'sc_edge', 'sc_arc', 'sc_arc_member',
-  'sc_const', 'sc_var',
-  'sc_node_struct', 'sc_node_tuple', 'sc_node_role', 'sc_node_no_role', 'sc_node_class', 'sc_node_abstract', 'sc_node_material',
-  'sc_edge_perm', 'sc_edge_temp',
-  'sc_edge_pos', 'sc_edge_neg', 'sc_edge_fuz'
-  ]%}
+{% set keynodes_list = KeynodeNames.CORE_TYPES
+    + KeynodeNames.CONST_TYPES
+    + KeynodeNames.NODE_TYPES
+    + KeynodeNames.ARC_PERM_TYPES
+    + KeynodeNames.ARC_POS_TYPES %}
 
 {# find system identifier keynode #}
 {{ names.find_sys_idtf_rel(found_name="found_nrel_sys_idtf") }}
diff --git a/db/tools/bootstrap/steps/lib/names.cypher.jinja b/db/tools/bootstrap/steps/lib/names.cypher.jinja
index 4af37a0..75f1b64 100644
--- a/db/tools/bootstrap/steps/lib/names.cypher.jinja
+++ b/db/tools/bootstrap/steps/lib/names.cypher.jinja
@@ -9,7 +9,7 @@ MATCH
       -[:{{Labels.SC_ARC}} { {{ types.arc_member_const_pos_perm() }} }]->
         (edge_sock_{{found_name}})
 WHERE 
-  (link_{{found_name}}.content = '{{Keynodes.NREL_SYS_IDTF}}') AND
+  (link_{{found_name}}.content = '{{KeynodeNames.NREL_SYS_IDTF}}') AND
   edge_sock_{{found_name}}.edge_id = id(edge_{{found_name}})
 {%- endmacro %}
 
diff --git a/docs/high_level_arch.drawio b/docs/high_level_arch.drawio
new file mode 100644
index 0000000..0b842d2
--- /dev/null
+++ b/docs/high_level_arch.drawio
@@ -0,0 +1 @@
+<mxfile host="Electron" modified="2021-10-23T16:22:49.960Z" agent="5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) draw.io/15.4.0 Chrome/91.0.4472.164 Electron/13.5.0 Safari/537.36" etag="-MzQ8FXbQKcQoGNlnH88" version="15.4.0" type="device"><diagram id="_MXVCpNhq2_oDS-9XibL" name="Page-1">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</diagram></mxfile>
\ No newline at end of file
diff --git a/packages.txt b/packages.txt
index f1b68b1..ae3df4d 100644
--- a/packages.txt
+++ b/packages.txt
@@ -1,3 +1,4 @@
+antlr4-python3-runtime
 Jinja2
 neo4j
 termcolor
diff --git a/web/backend/.gitignore b/web/backend/.gitignore
deleted file mode 100644
index 3507a4c..0000000
--- a/web/backend/.gitignore
+++ /dev/null
@@ -1 +0,0 @@
-config.ini
\ No newline at end of file