src/ZF/Cardinal.thy
changeset 81125 ec121999a9cb
parent 76217 8655344f1cf6
equal deleted inserted replaced
81124:6ce0c8d59f5a 81125:ec121999a9cb
    23 definition
    23 definition
    24   lesspoll :: "[i,i] \<Rightarrow> o"     (infixl \<open>\<prec>\<close> 50)  where
    24   lesspoll :: "[i,i] \<Rightarrow> o"     (infixl \<open>\<prec>\<close> 50)  where
    25     "A \<prec> B \<equiv> A \<lesssim> B \<and> \<not>(A \<approx> B)"
    25     "A \<prec> B \<equiv> A \<lesssim> B \<and> \<not>(A \<approx> B)"
    26 
    26 
    27 definition
    27 definition
    28   cardinal :: "i\<Rightarrow>i"           (\<open>|_|\<close>)  where
    28   cardinal :: "i\<Rightarrow>i"  (\<open>(\<open>open_block notation=\<open>mixfix cardinal\<close>\<close>|_|)\<close>)
    29     "|A| \<equiv> (\<mu> i. i \<approx> A)"
    29   where "|A| \<equiv> (\<mu> i. i \<approx> A)"
    30 
    30 
    31 definition
    31 definition
    32   Finite   :: "i\<Rightarrow>o"  where
    32   Finite   :: "i\<Rightarrow>o"  where
    33     "Finite(A) \<equiv> \<exists>n\<in>nat. A \<approx> n"
    33     "Finite(A) \<equiv> \<exists>n\<in>nat. A \<approx> n"
    34 
    34