src/HOL/ex/Unification.thy
changeset 42463 f270e3e18be5
parent 41460 ea56b98aee83
child 44367 74c08021ab2e
--- a/src/HOL/ex/Unification.thy	Fri Apr 22 15:57:43 2011 +0200
+++ b/src/HOL/ex/Unification.thy	Sat Apr 23 13:00:19 2011 +0200
@@ -31,8 +31,7 @@
   | Const 'a
   | App "'a trm" "'a trm" (infix "\<cdot>" 60)
 
-types
-  'a subst = "('a \<times> 'a trm) list"
+type_synonym 'a subst = "('a \<times> 'a trm) list"
 
 text {* Applying a substitution to a variable: *}