diff -r 262fc2c6371b -r 18905d086cbb scala/abacus.scala
--- a/scala/abacus.scala	Fri Mar 08 11:31:04 2013 +0000
+++ b/scala/abacus.scala	Sun Mar 10 07:10:50 2013 +0000
@@ -35,16 +35,16 @@
     case Goto(l) => if (l == old_jump) Goto(jump) else Goto(l)
   }))
 
-  def step(cf: AConfig) : AConfig = (nth_of(p, cf.s), cf.s) match {
-    case (None, _) => cf
-    case (Some(Inc(n)), s) => AConfig(s + 1, cf.regs + (n -> (dget(cf.regs, n) + 1)))
-    case (Some(Dec(n, l)), s) => {
+  def step(cf: AConfig) : AConfig = nth_of(p, cf.s) match {
+    case None => cf
+    case Some(Inc(n)) => AConfig(cf.s + 1, cf.regs + (n -> (dget(cf.regs, n) + 1)))
+    case Some(Dec(n, l)) => {
       if (dget(cf.regs, n) == 0) AConfig(l, cf.regs)
-      else AConfig(s + 1, cf.regs + (n -> (dget(cf.regs, n) - 1)))
+      else AConfig(cf.s + 1, cf.regs + (n -> (dget(cf.regs, n) - 1)))
     }
-    case (Some(Goto(l)), _) => AConfig(l, cf.regs)
-  }  
-
+    case Some(Goto(l)) => AConfig(l, cf.regs)
+  } 
+  
   def steps(cf: AConfig, n: Int) : AConfig = n match {
     case 0 => cf
     case n => steps(step(cf), n - 1)