src/HOL/Conditionally_Complete_Lattices.thy
changeset 63040 eb4ddd18d635
parent 62626 de25474ce728
child 63092 a949b2a5f51d
--- a/src/HOL/Conditionally_Complete_Lattices.thy	Sun Apr 24 21:31:14 2016 +0200
+++ b/src/HOL/Conditionally_Complete_Lattices.thy	Mon Apr 25 16:09:26 2016 +0200
@@ -590,7 +590,7 @@
     S = {a..<b} \<or>
     S = {a..b}"
 proof -
-  def lower \<equiv> "{x. \<exists>s\<in>S. s \<le> x}" and upper \<equiv> "{x. \<exists>s\<in>S. x \<le> s}"
+  define lower upper where "lower = {x. \<exists>s\<in>S. s \<le> x}" and "upper = {x. \<exists>s\<in>S. x \<le> s}"
   with ivl have "S = lower \<inter> upper"
     by auto
   moreover