let f be Form of V,V; ( f is hermitan & f is additiveSAF implies f is additiveFAF )
assume A1:
( f is hermitan & f is additiveSAF )
; f is additiveFAF
let v1 be Vector of V; BILINEAR:def 11 FunctionalFAF (f,v1) is additive
set F = FunctionalFAF (f,v1);
set F2 = FunctionalSAF (f,v1);
now for x, y being Vector of V holds (FunctionalFAF (f,v1)) . (x + y) = ((FunctionalFAF (f,v1)) . x) + ((FunctionalFAF (f,v1)) . y)let x,
y be
Vector of
V;
(FunctionalFAF (f,v1)) . (x + y) = ((FunctionalFAF (f,v1)) . x) + ((FunctionalFAF (f,v1)) . y)thus (FunctionalFAF (f,v1)) . (x + y) =
f . (
v1,
(x + y))
by BILINEAR:8
.=
(f . ((x + y),v1)) *'
by A1
.=
((FunctionalSAF (f,v1)) . (x + y)) *'
by BILINEAR:9
.=
(((FunctionalSAF (f,v1)) . x) + ((FunctionalSAF (f,v1)) . y)) *'
by A1, VECTSP_1:def 20
.=
((f . (x,v1)) + ((FunctionalSAF (f,v1)) . y)) *'
by BILINEAR:9
.=
((f . (x,v1)) + (f . (y,v1))) *'
by BILINEAR:9
.=
((f . (x,v1)) *') + ((f . (y,v1)) *')
by COMPLFLD:51
.=
(f . (v1,x)) + ((f . (y,v1)) *')
by A1
.=
(f . (v1,x)) + (f . (v1,y))
by A1
.=
((FunctionalFAF (f,v1)) . x) + (f . (v1,y))
by BILINEAR:8
.=
((FunctionalFAF (f,v1)) . x) + ((FunctionalFAF (f,v1)) . y)
by BILINEAR:8
;
verum end;
hence
FunctionalFAF (f,v1) is additive
; verum