--- a/src/HOL/Library/Mapping.thy Wed Aug 22 12:32:58 2018 +0000
+++ b/src/HOL/Library/Mapping.thy Wed Aug 22 12:32:58 2018 +0000
@@ -117,10 +117,6 @@
definition "lookup_default d m k = (case Mapping.lookup m k of None \<Rightarrow> d | Some v \<Rightarrow> v)"
-lemma [code abstract]:
- "lookup (Mapping f) = f"
- by (fact Mapping.lookup.abs_eq) (* FIXME lifting *)
-
lift_definition update :: "'a \<Rightarrow> 'b \<Rightarrow> ('a, 'b) mapping \<Rightarrow> ('a, 'b) mapping"
is "\<lambda>k v m. m(k \<mapsto> v)" parametric update_parametric .