src/HOL/Lattice/CompleteLattice.thy
changeset 10183 76f0f0f1c971
parent 10176 2e38e3c94990
child 10309 a7f961fb62c6
--- a/src/HOL/Lattice/CompleteLattice.thy	Tue Oct 10 23:43:23 2000 +0200
+++ b/src/HOL/Lattice/CompleteLattice.thy	Tue Oct 10 23:43:47 2000 +0200
@@ -80,8 +80,8 @@
 
 lemma is_Inf_Meet [intro?]: "is_Inf A (\<Sqinter>A)"
 proof (unfold Meet_def)
-  from ex_Inf show "is_Inf A (SOME inf. is_Inf A inf)"
-    by (rule someI_ex)
+  from ex_Inf
+  show "is_Inf A (SOME inf. is_Inf A inf)" ..
 qed
 
 lemma Meet_greatest [intro?]: "(\<And>a. a \<in> A \<Longrightarrow> x \<sqsubseteq> a) \<Longrightarrow> x \<sqsubseteq> \<Sqinter>A"
@@ -93,8 +93,8 @@
 
 lemma is_Sup_Join [intro?]: "is_Sup A (\<Squnion>A)"
 proof (unfold Join_def)
-  from ex_Sup show "is_Sup A (SOME sup. is_Sup A sup)"
-    by (rule someI_ex)
+  from ex_Sup
+  show "is_Sup A (SOME sup. is_Sup A sup)" ..
 qed
 
 lemma Join_least [intro?]: "(\<And>a. a \<in> A \<Longrightarrow> a \<sqsubseteq> x) \<Longrightarrow> \<Squnion>A \<sqsubseteq> x"