# HG changeset patch
# User atton
# Date 1477470725 0
# Node ID 783541c5ee4284339d4e5ae8c1b61f210c5657d3
# Parent  8ab5d27e615827bf77b17045c0127b80a8db8a0a
Fix eval1 to 1-step style

diff -r 8ab5d27e6158 -r 783541c5ee42 arith/Arith.hs
--- a/arith/Arith.hs	Wed Oct 26 08:19:46 2016 +0000
+++ b/arith/Arith.hs	Wed Oct 26 08:32:05 2016 +0000
@@ -30,7 +30,7 @@
 eval1 :: Term -> Either String Term
 eval1 (TmIf TmTrue  t _)    = return t
 eval1 (TmIf TmFalse _ f)    = return f
-eval1 (TmIf con t f)        = eval1 t >>= (\con' -> eval1 (TmIf con' t f))
+eval1 (TmIf con t f)        = eval1 con >>= (\con' -> return (TmIf con' t f))
 eval1 (TmSucc t)            = eval1 t >>= (\t' -> return $ TmSucc t')
 eval1 (TmPred TmZero)       = return $ TmZero
 eval1 (TmPred (TmSucc t))