let A, B be strict multMagma ; :: thesis: ( the carrier of A = product (Carrier F) & ( for f, g being Element of product (Carrier F)
for i being set st i in I holds
ex Fi being non empty multMagma ex h being Function st
( Fi = F . i & h = the multF of A . f,g & h . i = the multF of Fi . (f . i),(g . i) ) ) & the carrier of B = product (Carrier F) & ( for f, g being Element of product (Carrier F)
for i being set st i in I holds
ex Fi being non empty multMagma ex h being Function st
( Fi = F . i & h = the multF of B . f,g & h . i = the multF of Fi . (f . i),(g . i) ) ) implies A = B )
assume that
A14:
the carrier of A = product (Carrier F)
and
A15:
for f, g being Element of product (Carrier F)
for i being set st i in I holds
ex Fi being non empty multMagma ex h being Function st
( Fi = F . i & h = the multF of A . f,g & h . i = the multF of Fi . (f . i),(g . i) )
and
A16:
the carrier of B = product (Carrier F)
and
A17:
for f, g being Element of product (Carrier F)
for i being set st i in I holds
ex Fi being non empty multMagma ex h being Function st
( Fi = F . i & h = the multF of B . f,g & h . i = the multF of Fi . (f . i),(g . i) )
; :: thesis: A = B
for x, y being set st x in the carrier of A & y in the carrier of A holds
the multF of A . x,y = the multF of B . x,y
proof
let x,
y be
set ;
:: thesis: ( x in the carrier of A & y in the carrier of A implies the multF of A . x,y = the multF of B . x,y )
assume A18:
(
x in the
carrier of
A &
y in the
carrier of
A )
;
:: thesis: the multF of A . x,y = the multF of B . x,y
set P =
product (Carrier F);
reconsider x1 =
x,
y1 =
y as
Element of
product (Carrier F) by A14, A18;
[x1,y1] in [:the carrier of A,the carrier of A:]
by A18, ZFMISC_1:106;
then reconsider f = the
multF of
A . [x1,y1] as
Element of
product (Carrier F) by A14, FUNCT_2:7;
[x1,y1] in [:the carrier of B,the carrier of B:]
by A16, ZFMISC_1:106;
then reconsider g = the
multF of
B . [x1,y1] as
Element of
product (Carrier F) by A16, FUNCT_2:7;
dom (Carrier F) = I
by PBOOLE:def 3;
then A19:
(
dom f = I &
dom g = I )
by CARD_3:18;
for
i being
set st
i in I holds
f . i = g . i
hence
the
multF of
A . x,
y = the
multF of
B . x,
y
by A19, FUNCT_1:9;
:: thesis: verum
end;
hence
A = B
by A14, A16, BINOP_1:1; :: thesis: verum