# HG changeset patch # User lcp # Date 799319861 -7200 # Node ID 2f9f2ea26f8fa48c53737bc843a65addefd045f5 # Parent e57beb974dd77d7a384aedfdb51c8ec98447876b Simplified proof of Hausdorff_next_exists. diff -r e57beb974dd7 -r 2f9f2ea26f8f src/ZF/Zorn.ML --- a/src/ZF/Zorn.ML Fri Apr 28 15:38:15 1995 +0200 +++ b/src/ZF/Zorn.ML Mon May 01 11:17:41 1995 +0200 @@ -204,8 +204,6 @@ chain_subset_Pow RS subsetD, choice_super]) 1); (*Now, verify that it increases*) -by (rtac allI 1); -by (rtac impI 1); by (asm_simp_tac (ZF_ss addsimps [Pow_iff, subset_refl] setloop split_tac [expand_if]) 1); by (safe_tac ZF_cs);