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 12 FunctionalFAF f,v1 is additive
set F = FunctionalFAF f,v1;
set F2 = FunctionalSAF f,v1;
now 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:9
.=
(f . (x + y),v1) *'
by A1, Def5
.=
((FunctionalSAF f,v1) . (x + y)) *'
by BILINEAR:10
.=
(((FunctionalSAF f,v1) . x) + ((FunctionalSAF f,v1) . y)) *'
by A1, GRCAT_1:def 13
.=
((f . x,v1) + ((FunctionalSAF f,v1) . y)) *'
by BILINEAR:10
.=
((f . x,v1) + (f . y,v1)) *'
by BILINEAR:10
.=
((f . x,v1) *' ) + ((f . y,v1) *' )
by COMPLFLD:87
.=
(f . v1,x) + ((f . y,v1) *' )
by A1, Def5
.=
(f . v1,x) + (f . v1,y)
by A1, Def5
.=
((FunctionalFAF f,v1) . x) + (f . v1,y)
by BILINEAR:9
.=
((FunctionalFAF f,v1) . x) + ((FunctionalFAF f,v1) . y)
by BILINEAR:9
;
verum end;
hence
FunctionalFAF f,v1 is additive
by GRCAT_1:def 13; verum