# HG changeset patch # User paulson # Date 961576377 -7200 # Node ID 3a0912a127ec839758f667965dcb06a43a3b9469 # Parent 44cd0f9f8e5b0cff2c2b16f943362ba0dbcb3a29 new theorem UN_empty; it and Un_empty inserted by AddIffs diff -r 44cd0f9f8e5b -r 3a0912a127ec src/HOL/equalities.ML --- a/src/HOL/equalities.ML Wed Jun 21 10:31:34 2000 +0200 +++ b/src/HOL/equalities.ML Wed Jun 21 10:32:57 2000 +0200 @@ -366,7 +366,7 @@ Goal "(A Un B = {}) = (A = {} & B = {})"; by (blast_tac (claset() addEs [equalityCE]) 1); qed "Un_empty"; -Addsimps[Un_empty]; +AddIffs[Un_empty]; Goal "(A Un B <= C) = (A <= C & B <= C)"; by (Blast_tac 1); @@ -461,8 +461,8 @@ by (Blast_tac 1); qed "Union_Int_subset"; -Goal "(Union M = {}) = (! A : M. A = {})"; -by (blast_tac (claset() addEs [equalityCE]) 1); +Goal "(Union A = {}) = (ALL x:A. x={})"; +by Auto_tac; qed "Union_empty_conv"; AddIffs [Union_empty_conv]; @@ -596,6 +596,11 @@ by (Blast_tac 1); qed "INT_eq"; +Goal "(UNION A B = {}) = (ALL x:A. B x = {})"; +by Auto_tac; +qed "UN_empty"; +AddIffs [UN_empty]; + (*Distributive laws...*)