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