induct_true_def and induct_false_def are already contained in induct_rulify_fallback.
--- a/src/HOL/HOL.thy Mon May 03 14:35:10 2010 +0200
+++ b/src/HOL/HOL.thy Tue May 04 12:26:46 2010 +0200
@@ -1493,7 +1493,7 @@
Context.theory_map (Induct.map_simpset (fn ss => ss
setmksimps (fn ss => Simpdata.mksimps Simpdata.mksimps_pairs ss #>
map (Simplifier.rewrite_rule (map Thm.symmetric
- @{thms induct_rulify_fallback induct_true_def induct_false_def})))
+ @{thms induct_rulify_fallback})))
addsimprocs
[Simplifier.simproc @{theory} "swap_induct_false"
["induct_false ==> PROP P ==> PROP Q"]