# HG changeset patch # User oheimb # Date 890750768 -3600 # Node ID 35b47e36e6151f87503c0de711d6c157ba3f72dc # Parent 2b8ead8e9393bcbd50604d0f678ebdbe27bb8d7f added finite_acyclic_wf_converse diff -r 2b8ead8e9393 -r 35b47e36e615 src/HOL/WF_Rel.ML --- a/src/HOL/WF_Rel.ML Mon Mar 23 13:56:53 1998 +0100 +++ b/src/HOL/WF_Rel.ML Tue Mar 24 15:46:08 1998 +0100 @@ -117,6 +117,11 @@ by (Asm_full_simp_tac 1); qed_spec_mp "finite_acyclic_wf"; +qed_goal "finite_acyclic_wf_converse" thy + "ÄX. Ëfinite r; acyclic rÌ êë wf (r^-1)" (K [ + etac (finite_converse RS iffD2 RS finite_acyclic_wf) 1, + etac (acyclic_converse RS iffD2) 1]); + goal thy "!!r. finite r ==> wf r = acyclic r"; by (blast_tac (claset() addIs [finite_acyclic_wf,wf_acyclic]) 1); qed "wf_iff_acyclic_if_finite";