--- a/src/HOL/Set.thy Sun Aug 01 23:18:13 2021 +0200
+++ b/src/HOL/Set.thy Mon Aug 02 10:01:06 2021 +0000
@@ -7,7 +7,7 @@
section \<open>Set theory for higher-order logic\<close>
theory Set
- imports Lattices
+ imports Lattices Boolean_Algebra
begin
subsection \<open>Sets as predicates\<close>