diff -r fd2558014196 -r 7655e6369c9f src/HOL/Library/Finite_Map.thy
--- a/src/HOL/Library/Finite_Map.thy	Wed Mar 07 17:39:18 2018 +0100
+++ b/src/HOL/Library/Finite_Map.thy	Wed Mar 07 19:02:22 2018 +0100
@@ -6,6 +6,7 @@
 
 theory Finite_Map
   imports FSet AList
+  abbrevs "(=" = "\<subseteq>\<^sub>f"
 begin
 
 subsection \<open>Auxiliary constants and lemmas over @{type map}\<close>