diff -r 9b1c15c3eb6f -r f618dd4de24a progs/re3.scala
--- a/progs/re3.scala	Wed Sep 25 11:24:34 2019 +0100
+++ b/progs/re3.scala	Wed Sep 25 23:56:36 2019 +0100
@@ -63,21 +63,10 @@
   case c::s => ders(s, simp(der(c, r)))
 }
 
-// the derivative w.r.t. a string (iterates der)
-def dersp(s: List[Char], r: Rexp) : Rexp = s match {
-  case Nil => r
-  case c::s => dersp(s, der(c, r))
-}
-
 
 // the main matcher function
 def matcher(r: Rexp, s: String) : Boolean = nullable(ders(s.toList, r))
 
-// tests
-val q = SEQ(SEQ(CHAR('x'), CHAR('y')), CHAR('z'))
-dersp("x".toList, q)
-dersp("xy".toList, q)
-dersp("xyz".toList, q)
 
 // one or zero
 def OPT(r: Rexp) = ALT(r, ONE)
@@ -99,21 +88,13 @@
 
 
 //test: (a?{n}) (a{n})
-for (i <- 1 to 7001 by 1000) {
-  println(i + " " + "%.5f".format(time_needed(2, matcher(EVIL1(i), "a" * i))))
-}
-
-for (i <- 1 to 7001 by 1000) {
-  println(i + " " + "%.5f".format(time_needed(2, matcher(EVIL1(i), "a" * i))))
+for (i <- 0 to 7000 by 1000) {
+  println(f"$i: ${time_needed(2, matcher(EVIL1(i), "a" * i))}%.5f")
 }
 
 //test: (a*)* b
-for (i <- 1 to 6000001 by 500000) {
-  println(i + " " + "%.5f".format(time_needed(2, matcher(EVIL2, "a" * i))))
-}
-
-for (i <- 1 to 6000001 by 500000) {
-  println(i + " " + "%.5f".format(time_needed(2, matcher(EVIL2, "a" * i))))
+for (i <- 0 to 6000000 by 500000) {
+  println(f"$i: ${time_needed(2, matcher(EVIL2, "a" * i))}%.5f")
 }