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
A17: the carrier of A = product (Carrier F) and
A18: 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
A19: the carrier of B = product (Carrier F) and
A20: 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

set P = product (Carrier F);
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 that
A21: x in the carrier of A and
A22: y in the carrier of A ; :: thesis: the multF of A . x,y = the multF of B . x,y
reconsider x1 = x, y1 = y as Element of product (Carrier F) by A17, A21, A22;
[x1,y1] in [:the carrier of A,the carrier of A:] by A21, A22, ZFMISC_1:106;
then reconsider f = the multF of A . [x1,y1] as Element of product (Carrier F) by A17, FUNCT_2:7;
[x1,y1] in [:the carrier of B,the carrier of B:] by A19, ZFMISC_1:106;
then reconsider g = the multF of B . [x1,y1] as Element of product (Carrier F) by A19, FUNCT_2:7;
A23: dom (Carrier F) = I by PARTFUN1:def 4;
then A24: dom g = I by CARD_3:18;
A25: for i being set st i in I holds
f . i = g . i

proof

let i be set ; :: thesis: ( i in I implies f . i = g . i )
assume A26: i in I ; :: thesis: f . i = g . i
then A27: ex Gi being non empty multMagma ex h2 being Function st
( Gi = F . i & h2 = the multF of B . x1,y1 & h2 . i = the multF of Gi . (x1 . i),(y1 . i) ) by A20;
ex Fi being non empty multMagma ex h1 being Function st
( Fi = F . i & h1 = the multF of A . x1,y1 & h1 . i = the multF of Fi . (x1 . i),(y1 . i) ) by A18, A26;
hence f . i = g . i by A27; :: thesis: verum

end;

dom f = I by A23, CARD_3:18;
hence the multF of A . x,y = the multF of B . x,y by A24, A25, FUNCT_1:9; :: thesis: verum

end;

hence A = B by A17, A19, BINOP_1:1; :: thesis: verum