let I be set ; for A, B being ManySortedSet of I st A is_transformable_to B holds
for f being ManySortedFunction of I st doms f = A & rngs f c= B holds
f is ManySortedFunction of A,B
let A, B be ManySortedSet of I; ( A is_transformable_to B implies for f being ManySortedFunction of I st doms f = A & rngs f c= B holds
f is ManySortedFunction of A,B )
assume A1:
for i being set st i in I & B . i = {} holds
A . i = {}
; PZFMISC1:def 3 for f being ManySortedFunction of I st doms f = A & rngs f c= B holds
f is ManySortedFunction of A,B
let f be ManySortedFunction of I; ( doms f = A & rngs f c= B implies f is ManySortedFunction of A,B )
assume that
A2:
doms f = A
and
A3:
rngs f c= B
; f is ManySortedFunction of A,B
let i be set ; PBOOLE:def 18 ( not i in I or f . i is Element of bool [:(A . i),(B . i):] )
assume A4:
i in I
; f . i is Element of bool [:(A . i),(B . i):]
then reconsider J = I as non empty set ;
reconsider s = i as Element of J by A4;
A5:
dom (f . s) = A . s
by A2, MSSUBFAM:14;
rng (f . s) = (rngs f) . s
by MSSUBFAM:13;
then A6:
rng (f . s) c= B . s
by A3, PBOOLE:def 5;
( B . s = {} implies A . s = {} )
by A1;
hence
f . i is Element of bool [:(A . i),(B . i):]
by A5, A6, FUNCT_2:def 1, RELSET_1:11; verum