let v be Vector of V; ZMODLAT1:def 29 FrFunctionalFAF ((FrFormFunctional (f,g)),v) is homogeneous
set fg = FrFormFunctional (f,g);
set F = FrFunctionalFAF ((FrFormFunctional (f,g)),v);
let y be Vector of W; ZMODLAT1:def 22 for r being Scalar of holds (FrFunctionalFAF ((FrFormFunctional (f,g)),v)) . (r * y) = r * ((FrFunctionalFAF ((FrFormFunctional (f,g)),v)) . y)
let r be Scalar of ; (FrFunctionalFAF ((FrFormFunctional (f,g)),v)) . (r * y) = r * ((FrFunctionalFAF ((FrFormFunctional (f,g)),v)) . y)
A1:
FrFunctionalFAF ((FrFormFunctional (f,g)),v) = (f . v) * g
by HTh24;
hence (FrFunctionalFAF ((FrFormFunctional (f,g)),v)) . (r * y) =
(f . v) * (g . (r * y))
by HDef6
.=
(f . v) * (r * (g . y))
by HDef8
.=
r * ((f . v) * (g . y))
.=
r * ((FrFunctionalFAF ((FrFormFunctional (f,g)),v)) . y)
by A1, HDef6
;
verum