src/HOL/Rat.thy

--- a/src/HOL/Rat.thy	Mon May 21 16:36:48 2012 +0200
+++ b/src/HOL/Rat.thy	Mon May 21 16:37:28 2012 +0200
@@ -1125,7 +1125,6 @@
 
 text {* De-register @{text "rat"} as a quotient type: *}
 
-setup {* Context.theory_map (Lifting_Info.update_quotients @{type_name rat}
-  {quot_thm = @{thm identity_quotient [where 'a=rat]}}) *}
+declare Quotient_rat[quot_del]
 
 end