--- a/progs/nfa.scala	Wed Oct 24 13:07:13 2018 +0100
+++ b/progs/nfa.scala	Wed Oct 24 16:03:07 2018 +0100
@@ -7,7 +7,7 @@
 // type abbreviation for partial functions
 type :=>[A, B] = PartialFunction[A, B]
 
-// return an empty set when not defined
+// return an empty set, when parial function is not defined
 def applyOrElse[A, B](f: A :=> Set[B], x: A) : Set[B] =
   Try(f(x)) getOrElse Set[B]()