let G be RealNormSpace-Sequence; for i being Element of dom G
for x, y being Point of (product G)
for xi being Point of (G . i) st y = (reproj (i,x)) . xi holds
(proj i) . y = xi
let i be Element of dom G; for x, y being Point of (product G)
for xi being Point of (G . i) st y = (reproj (i,x)) . xi holds
(proj i) . y = xi
let x, y be Point of (product G); for xi being Point of (G . i) st y = (reproj (i,x)) . xi holds
(proj i) . y = xi
let xi be Point of (G . i); ( y = (reproj (i,x)) . xi implies (proj i) . y = xi )
assume A1:
y = (reproj (i,x)) . xi
; (proj i) . y = xi
A2:
y = x +* (i,xi)
by A1, Def4;
x in the carrier of (product G)
;
then
x in product (carr G)
by Th10;
then consider g being Function such that
A3:
( x = g & dom g = dom (carr G) & ( for y being object st y in dom (carr G) holds
g . y in (carr G) . y ) )
by CARD_3:def 5;
A4:
i in dom G
;
A5:
i in dom x
by Lm1, A4, A3;
y is Element of product (carr G)
by Th10;
then
(proj i) . y = (x +* (i,xi)) . i
by A2, Def3;
hence
(proj i) . y = xi
by A5, FUNCT_7:31; verum