src/HOL/Code_Numeral.thy
changeset 50849 b27bbb021df1
parent 49446 6efff142bb54
child 50977 a8cc904a6820
equal deleted inserted replaced
50848:1d80798e8d8a 50849:b27bbb021df1
    11   mapped to target-language builtin numerals.
    11   mapped to target-language builtin numerals.
    12 *}
    12 *}
    13 
    13 
    14 subsection {* Datatype of target language numerals *}
    14 subsection {* Datatype of target language numerals *}
    15 
    15 
    16 typedef (open) code_numeral = "UNIV \<Colon> nat set"
    16 typedef code_numeral = "UNIV \<Colon> nat set"
    17   morphisms nat_of of_nat ..
    17   morphisms nat_of of_nat ..
    18 
    18 
    19 lemma of_nat_nat_of [simp]:
    19 lemma of_nat_nat_of [simp]:
    20   "of_nat (nat_of k) = k"
    20   "of_nat (nat_of k) = k"
    21   by (rule nat_of_inverse)
    21   by (rule nat_of_inverse)