changeset 5139 | 013ea0f023e3 |
parent 4462 | fefe21f761d7 |
child 5309 | 01c2b317da88 |
--- a/src/FOL/IFOL.ML Mon Jul 13 17:46:20 1998 +0200 +++ b/src/FOL/IFOL.ML Tue Jul 14 13:29:39 1998 +0200 @@ -238,7 +238,9 @@ (*Substitution: rule and tactic*) bind_thm ("ssubst", sym RS subst); -fun stac th = CHANGED o rtac (th RS ssubst); + +(*Fails unless the substitution has an effect*) +fun stac th = CHANGED_GOAL (rtac (th RS ssubst)); (*A special case of ex1E that would otherwise need quantifier expansion*) qed_goal "ex1_equalsE" IFOL.thy