let V be non empty set ; for A, B being Element of V
for m being Element of Maps V st m in Maps A,B holds
m = [[A,B],(m `2 )]
let A, B be Element of V; for m being Element of Maps V st m in Maps A,B holds
m = [[A,B],(m `2 )]
let m be Element of Maps V; ( m in Maps A,B implies m = [[A,B],(m `2 )] )
assume
m in Maps A,B
; m = [[A,B],(m `2 )]
then A1:
ex f being Element of Funcs V st
( m = [[A,B],f] & [[A,B],f] in Maps V )
;
m = [[(dom m),(cod m)],(m `2 )]
by Th8;
hence
m = [[A,B],(m `2 )]
by A1, ZFMISC_1:33; verum