diff -r b47e140bcccd -r 47a299e7010f progs/nfa.scala
--- a/progs/nfa.scala	Thu Jul 25 14:39:37 2019 +0100
+++ b/progs/nfa.scala	Sun Jul 28 01:00:41 2019 +0100
@@ -4,18 +4,18 @@
 // needs :load dfa.scala   for states
 
 
-// type abbreviation for partial functions
+// a type abbreviation for partial functions
 type :=>[A, B] = PartialFunction[A, B]
 
-// return an empty set, when parial function is not defined
+// return an empty set, when a parial function is not defined
 def applyOrElse[A, B](f: A :=> Set[B], x: A) : Set[B] =
   Try(f(x)) getOrElse Set[B]()
 
 
 // NFAs
-case class NFA[A, C](starts: Set[A],           // starting states
-                     delta: (A, C) :=> Set[A], // transition function
-                     fins:  A => Boolean) {    // final states 
+case class NFA[A, C](starts: Set[A],           // the starting states
+                     delta: (A, C) :=> Set[A], // the transition function
+                     fins:  A => Boolean) {    // the final states 
 
   // given a state and a character, what is the set of 
   // next states? if there is none => empty set