let f be Form of V,V; ( f is hermitan & f is additiveFAF implies f is additiveSAF )
assume A1:
( f is hermitan & f is additiveFAF )
; f is additiveSAF
let w be Vector of V; BILINEAR:def 13 FunctionalSAF f,w is additive
set F = FunctionalSAF f,w;
set F1 = FunctionalFAF f,w;
now let x,
y be
Vector of
V;
(FunctionalSAF f,w) . (x + y) = ((FunctionalSAF f,w) . x) + ((FunctionalSAF f,w) . y)thus (FunctionalSAF f,w) . (x + y) =
f . (x + y),
w
by BILINEAR:10
.=
(f . w,(x + y)) *'
by A1, Def5
.=
((FunctionalFAF f,w) . (x + y)) *'
by BILINEAR:9
.=
(((FunctionalFAF f,w) . x) + ((FunctionalFAF f,w) . y)) *'
by A1, GRCAT_1:def 13
.=
((f . w,x) + ((FunctionalFAF f,w) . y)) *'
by BILINEAR:9
.=
((f . w,x) + (f . w,y)) *'
by BILINEAR:9
.=
((f . w,x) *' ) + ((f . w,y) *' )
by COMPLFLD:87
.=
(f . x,w) + ((f . w,y) *' )
by A1, Def5
.=
(f . x,w) + (f . y,w)
by A1, Def5
.=
((FunctionalSAF f,w) . x) + (f . y,w)
by BILINEAR:10
.=
((FunctionalSAF f,w) . x) + ((FunctionalSAF f,w) . y)
by BILINEAR:10
;
verum end;
hence
FunctionalSAF f,w is additive
by GRCAT_1:def 13; verum