src/ZF/AC/AC_Equiv.thy
changeset 67443 3abf6a722518
parent 65449 c82e63b11b8b
child 76213 e44d86131648
equal deleted inserted replaced
67442:f075640b8868 67443:3abf6a722518
   122 
   122 
   123 locale AC18 =
   123 locale AC18 =
   124   assumes AC18: "A\<noteq>0 & (\<forall>a \<in> A. B(a) \<noteq> 0) \<longrightarrow>
   124   assumes AC18: "A\<noteq>0 & (\<forall>a \<in> A. B(a) \<noteq> 0) \<longrightarrow>
   125     ((\<Inter>a \<in> A. \<Union>b \<in> B(a). X(a,b)) =   
   125     ((\<Inter>a \<in> A. \<Union>b \<in> B(a). X(a,b)) =   
   126       (\<Union>f \<in> \<Prod>a \<in> A. B(a). \<Inter>a \<in> A. X(a, f`a)))"
   126       (\<Union>f \<in> \<Prod>a \<in> A. B(a). \<Inter>a \<in> A. X(a, f`a)))"
   127   \<comment>"AC18 cannot be expressed within the object-logic"
   127   \<comment> \<open>AC18 cannot be expressed within the object-logic\<close>
   128 
   128 
   129 definition
   129 definition
   130     "AC19 == \<forall>A. A\<noteq>0 & 0\<notin>A \<longrightarrow> ((\<Inter>a \<in> A. \<Union>b \<in> a. b) =   
   130     "AC19 == \<forall>A. A\<noteq>0 & 0\<notin>A \<longrightarrow> ((\<Inter>a \<in> A. \<Union>b \<in> a. b) =   
   131                    (\<Union>f \<in> (\<Prod>B \<in> A. B). \<Inter>a \<in> A. f`a))"
   131                    (\<Union>f \<in> (\<Prod>B \<in> A. B). \<Inter>a \<in> A. f`a))"
   132 
   132