let x, y be FinSequence of COMPLEX ; :: thesis: ( len x = len y implies (mlt x,y) *' = mlt (x *' ),(y *' ) )
assume A1:
len x = len y
; :: thesis: (mlt x,y) *' = mlt (x *' ),(y *' )
A2:
len ((mlt x,y) *' ) = len (mlt x,y)
by COMPLSP2:def 1;
A3:
len (y *' ) = len y
by COMPLSP2:def 1;
A4:
len (x *' ) = len x
by COMPLSP2:def 1;
then
len (mlt (x *' ),(y *' )) = len (x *' )
by A1, A3, FINSEQ_2:86;
then A5:
len ((mlt x,y) *' ) = len (mlt (x *' ),(y *' ))
by A1, A2, A4, FINSEQ_2:86;
for i being Nat st 1 <= i & i <= len ((mlt x,y) *' ) holds
((mlt x,y) *' ) . i = (mlt (x *' ),(y *' )) . i
proof
let i be
Nat;
:: thesis: ( 1 <= i & i <= len ((mlt x,y) *' ) implies ((mlt x,y) *' ) . i = (mlt (x *' ),(y *' )) . i )
((mlt x,y) *' ) . i =
((mlt y,((x *' ) *' )) *' ) . i
by COMPLSP2:22
.=
(mlt (x *' ),(y *' )) . i
by A1, A4, Th25
;
hence
( 1
<= i &
i <= len ((mlt x,y) *' ) implies
((mlt x,y) *' ) . i = (mlt (x *' ),(y *' )) . i )
;
:: thesis: verum
end;
hence
(mlt x,y) *' = mlt (x *' ),(y *' )
by A5, FINSEQ_1:18; :: thesis: verum