--- a/progs/re1.scala	Tue Oct 18 10:43:26 2016 +0100
+++ b/progs/re1.scala	Tue Oct 18 11:13:37 2016 +0100
@@ -5,12 +5,6 @@
 case class ALT(r1: Rexp, r2: Rexp) extends Rexp 
 case class SEQ(r1: Rexp, r2: Rexp) extends Rexp 
 case class STAR(r: Rexp) extends Rexp 
-case class RANGE(cs: List[Char]) extends Rexp
-case class PLUS(r: Rexp) extends Rexp
-case class OPT(r: Rexp) extends Rexp
-case class NTIMES(r: Rexp, n : Int) extends Rexp
-case class NMTIMES(r: Rexp, n : Int, m : Int) extends Rexp
-
 
 // nullable function: tests whether the regular 
 // expression can recognise the empty string