let f1, f2 be Relation of [:(Seg n),(Seg m):]; ( ( for x being set st x in [:(Seg n),(Seg m):] holds
for i, j being Element of NAT st x = [i,j] holds
Im f1,x = [:(Im (Nbdl1 n),i),(Im (Nbdl1 m),j):] ) & ( for x being set st x in [:(Seg n),(Seg m):] holds
for i, j being Element of NAT st x = [i,j] holds
Im f2,x = [:(Im (Nbdl1 n),i),(Im (Nbdl1 m),j):] ) implies f1 = f2 )
assume that
A10:
for x being set st x in [:(Seg n),(Seg m):] holds
for i, j being Element of NAT st x = [i,j] holds
Im f1,x = [:(Im (Nbdl1 n),i),(Im (Nbdl1 m),j):]
and
A11:
for x being set st x in [:(Seg n),(Seg m):] holds
for i, j being Element of NAT st x = [i,j] holds
Im f2,x = [:(Im (Nbdl1 n),i),(Im (Nbdl1 m),j):]
; f1 = f2
for x being set st x in [:(Seg n),(Seg m):] holds
Im f1,x = Im f2,x
proof
let x be
set ;
( x in [:(Seg n),(Seg m):] implies Im f1,x = Im f2,x )
assume A12:
x in [:(Seg n),(Seg m):]
;
Im f1,x = Im f2,x
then consider u,
y being
set such that A13:
(
u in Seg n &
y in Seg m )
and A14:
x = [u,y]
by ZFMISC_1:def 2;
reconsider i =
u,
j =
y as
Element of
NAT by A13;
Im f1,
x = [:(Im (Nbdl1 n),i),(Im (Nbdl1 m),j):]
by A10, A12, A14;
hence
Im f1,
x = Im f2,
x
by A11, A12, A14;
verum
end;
hence
f1 = f2
by RELSET_1:54; verum