Add some comments

DFA.fs

@@ -21,9 +21,15 @@ let validateDFA (dfa:DFA) =
         |> List.length < 1
 
     let deltaIsComplete = 
+        // Gets the cartesian product of states * sigma
         dfa.states
         |> List.collect (fun x -> dfa.sigma |> List.map (fun y -> (x, y)))
+
+        // Processes all tuples through delta
         |> List.map (fun x -> dfa.delta (fst x) (snd x))
+
+        // Checks if there is any result from delta which is not
+        // a valid state
         |> List.filter (fun x -> not (List.contains x dfa.states))
         |> List.length < 1