1.1 --- a/src/HOL/String.thy	Wed Nov 20 10:59:12 2013 +0100
     1.2 +++ b/src/HOL/String.thy	Wed Nov 20 11:10:05 2013 +0100
     1.3 @@ -358,6 +358,8 @@
     1.4  typedef literal = "UNIV :: string set"
     1.5    morphisms explode STR ..
     1.6  
     1.7 +setup_lifting (no_code) type_definition_literal
     1.8 +
     1.9  instantiation literal :: size
    1.10  begin
    1.11  
    1.12 @@ -372,16 +374,14 @@
    1.13  instantiation literal :: equal
    1.14  begin
    1.15  
    1.16 -definition equal_literal :: "literal \<Rightarrow> literal \<Rightarrow> bool"
    1.17 -where
    1.18 -  "equal_literal s1 s2 \<longleftrightarrow> explode s1 = explode s2"
    1.19 +lift_definition equal_literal :: "literal \<Rightarrow> literal \<Rightarrow> bool" is "op =" .
    1.20  
    1.21 -instance
    1.22 -proof
    1.23 -qed (auto simp add: equal_literal_def explode_inject)
    1.24 +instance by intro_classes (transfer, simp)
    1.25  
    1.26  end
    1.27  
    1.28 +declare equal_literal.rep_eq[code]
    1.29 +
    1.30  lemma [code nbe]:
    1.31    fixes s :: "String.literal"
    1.32    shows "HOL.equal s s \<longleftrightarrow> True"
    1.33 @@ -391,7 +391,6 @@
    1.34    "STR xs = STR ys \<longleftrightarrow> xs = ys"
    1.35    by (simp add: STR_inject)
    1.36  
    1.37 -
    1.38  subsection {* Code generator *}
    1.39  
    1.40  ML_file "Tools/string_code.ML"