--- a/progs/automata/thompson.sc	Sun Oct 01 09:46:44 2023 +0100
+++ b/progs/automata/thompson.sc	Sun Oct 01 10:57:32 2023 +0100
@@ -47,7 +47,7 @@
 
 // for composing an eNFA transition with an NFA transition
 // | is for set union
-implicit def nfaOps(f: eNFAtrans) = new {
+extension (f: eNFAtrans) {
   def +++(g: NFAtrans) : eNFAtrans = 
   { case (q, None) =>  applyOrElse(f, (q, None)) 
     case (q, Some(c)) => applyOrElse(f, (q, Some(c))) | applyOrElse(g, (q, c))  }