let h be Function; ( dom <:<*h*>:> = dom h & ( for x being set st x in dom h holds
<:<*h*>:> . x = <*(h . x)*> ) )
A1:
1 in Seg 1
by FINSEQ_1:4, TARSKI:def 1;
A2:
( rng <:<*h*>:> c= product (rngs <*h*>) & rngs <*h*> = <*(rng h)*> )
by Th33, Th49;
thus A3: dom <:<*h*>:> =
meet (doms <*h*>)
by Th49
.=
meet <*(dom h)*>
by Th33
.=
dom h
by Th39
; for x being set st x in dom h holds
<:<*h*>:> . x = <*(h . x)*>
let x be set ; ( x in dom h implies <:<*h*>:> . x = <*(h . x)*> )
assume A4:
x in dom h
; <:<*h*>:> . x = <*(h . x)*>
then
<:<*h*>:> . x in rng <:<*h*>:>
by A3, FUNCT_1:def 5;
then consider g being Function such that
A5:
<:<*h*>:> . x = g
and
A6:
dom g = dom <*(rng h)*>
and
for y being set st y in dom <*(rng h)*> holds
g . y in <*(rng h)*> . y
by A2, CARD_3:def 5;
A7:
dom g = Seg 1
by A6, FINSEQ_1:55;
( dom <*h*> = Seg 1 & <*h*> . 1 = h )
by FINSEQ_1:55, FINSEQ_1:57;
then A8:
(uncurry <*h*>) . (1,x) = h . x
by A4, A1, FUNCT_5:45;
reconsider g = g as FinSequence by A7, FINSEQ_1:def 2;
A9:
len g = 1
by A7, FINSEQ_1:def 3;
g . 1 = (uncurry <*h*>) . (1,x)
by A3, A4, A5, A7, A1, Th51;
hence
<:<*h*>:> . x = <*(h . x)*>
by A5, A8, A9, FINSEQ_1:57; verum