let P, Q be Function of [:X,(product F):], product F; :: thesis: ( ( for x being Element of X
for d being Element of product F
for i being Element of dom F holds (P . x,d) . i = (p . i) . x,(d . i) ) & ( for x being Element of X
for d being Element of product F
for i being Element of dom F holds (Q . x,d) . i = (p . i) . x,(d . i) ) implies P = Q )
assume that
A5:
for x being Element of X
for f being Element of product F
for i being Element of dom F holds (P . x,f) . i = (p . i) . x,(f . i)
and
A6:
for x being Element of X
for f being Element of product F
for i being Element of dom F holds (Q . x,f) . i = (p . i) . x,(f . i)
; :: thesis: P = Q
now let x be
Element of
X;
:: thesis: for f being Element of product F
for i being Element of dom F holds (P . x,f) . i = (Q . x,f) . ilet f be
Element of
product F;
:: thesis: for i being Element of dom F holds (P . x,f) . i = (Q . x,f) . ilet i be
Element of
dom F;
:: thesis: (P . x,f) . i = (Q . x,f) . i
(P . x,f) . i = (p . i) . x,
(f . i)
by A5;
hence
(P . x,f) . i = (Q . x,f) . i
by A6;
:: thesis: verum end;
hence
P = Q
by Th5; :: thesis: verum