--- a/progs/app6.scala	Sun Sep 30 12:01:14 2018 +0100
+++ b/progs/app6.scala	Sun Sep 30 23:38:38 2018 +0100
@@ -16,7 +16,6 @@
       case (r1s, r2s) => SEQ(r1s, r2s)
     }
   }
-  case NTIMES(r, n) => NTIMES(simp(r), n)    
   case r => r
 }