let y be Vector of W; BILINEAR:def 15 FunctionalSAF (FormFunctional f,g),y is homogeneous
set fg = FormFunctional f,g;
set F = FunctionalSAF (FormFunctional f,g),y;
let v be Vector of V; HAHNBAN1:def 12 for b1 being Element of the carrier of K holds (FunctionalSAF (FormFunctional f,g),y) . (b1 * v) = b1 * ((FunctionalSAF (FormFunctional f,g),y) . v)
let r be Scalar of ; (FunctionalSAF (FormFunctional f,g),y) . (r * v) = r * ((FunctionalSAF (FormFunctional f,g),y) . v)
A1:
FunctionalSAF (FormFunctional f,g),y = (g . y) * f
by Th26;
hence (FunctionalSAF (FormFunctional f,g),y) . (r * v) =
(g . y) * (f . (r * v))
by HAHNBAN1:def 9
.=
(g . y) * (r * (f . v))
by HAHNBAN1:def 12
.=
r * ((g . y) * (f . v))
by GROUP_1:def 4
.=
r * ((FunctionalSAF (FormFunctional f,g),y) . v)
by A1, HAHNBAN1:def 9
;
verum