Update index.html

docs/index.html

@@ -13,7 +13,8 @@ <h2>Abstract</h2>
  The type of relation is an implication. We can see that simple rules are relate to complex rule by an implication. 
  Rule 255 is relate to all others rules.</p>
  <h2>Basic concepts</h2>
- <p>Starting by this point <a href="https://list.iupui.edu/sympa/arc/peirce-l/2021-04/msg00095.html">p-list</a>, 
+ <p>Starting by these points <a href="https://list.iupui.edu/sympa/arc/peirce-l/2021-04/msg00095.html">p-list A</a> and 
+  <a href="https://list.iupui.edu/sympa/arc/peirce-l/2021-06/msg00019.html">p-list B</a>, 
   where implication is defined as an inclusion of truth table, we can define the rule that a prepositional sentence A implies 
   another prepositional sentence B if all the 1s of A truth table are also 1s in B truth table. 
   So if A in 3 variable propositional sentences is represented by an octet, we can say that 00001001 implies 00011001