changeset 71840 | 8ed78bb0b915 |
parent 71827 | 5e315defb038 |
child 72090 | 5d17e7a0825a |
--- a/src/HOL/Library/Infinite_Set.thy Thu May 14 10:26:33 2020 +0100 +++ b/src/HOL/Library/Infinite_Set.thy Thu May 14 13:44:44 2020 +0200 @@ -371,8 +371,9 @@ then show ?case by simp next case (insert a A) - with R show ?case - by (metis empty_iff insert_iff) (* somewhat slow *) + have False + using R(1)[of a] R(2)[of _ a] insert(3,4) by blast + thus ?case .. qed corollary Union_maximal_sets: