--- a/thys/turing_basic.thy Sat Jan 19 12:45:14 2013 +0000
+++ b/thys/turing_basic.thy Sat Jan 19 12:46:28 2013 +0000
@@ -223,12 +223,6 @@
\<exists>n'. \<not> is_final (steps (1, tp) A n') \<and> steps (1, tp) A (Suc n') = (0, tp')"
and h: " steps (1, tp) A (Suc n) = (0, tp')"
from h show "\<exists>n'. \<not> is_final (steps (1, tp) A n') \<and> steps (1, tp) A (Suc n') = (0, tp')"
- (*
- apply(simp add: step_red del: steps.simps)
- apply(case_tac "(steps (Suc 0, tp) A n)")
- apply(case_tac "a = 0")
- apply(simp)
- *)
proof(simp add: step_red del: steps.simps,
case_tac "(steps (Suc 0, tp) A n)", case_tac "a = 0", simp)
fix a b c