set lf = LQForm f;
thus LQForm f is additiveFAF :: thesis: LQForm f is homogeneousFAF
proof
let A be Vector of (VectQuot V,(LKer f)); :: according to BILINEAR:def 12 :: thesis: FunctionalFAF (LQForm f),A is additive
set flf = FunctionalFAF (LQForm f),A;
consider v being Vector of V such that
A1: A = v + (LKer f) by VECTSP10:23;
let w, t be Vector of W; :: according to HAHNBAN1:def 11 :: thesis: (FunctionalFAF (LQForm f),A) . (w + t) = ((FunctionalFAF (LQForm f),A) . w) + ((FunctionalFAF (LQForm f),A) . t)
thus (FunctionalFAF (LQForm f),A) . (w + t) = (LQForm f) . A,(w + t) by Th9
.= f . v,(w + t) by A1, Def21
.= (f . v,w) + (f . v,t) by Th28
.= ((LQForm f) . A,w) + (f . v,t) by A1, Def21
.= ((LQForm f) . A,w) + ((LQForm f) . A,t) by A1, Def21
.= ((FunctionalFAF (LQForm f),A) . w) + ((LQForm f) . A,t) by Th9
.= ((FunctionalFAF (LQForm f),A) . w) + ((FunctionalFAF (LQForm f),A) . t) by Th9 ; :: thesis: verum
end;
let A be Vector of (VectQuot V,(LKer f)); :: according to BILINEAR:def 14 :: thesis: FunctionalFAF (LQForm f),A is homogeneous
set flf = FunctionalFAF (LQForm f),A;
consider v being Vector of V such that
A2: A = v + (LKer f) by VECTSP10:23;
let w be Vector of W; :: according to HAHNBAN1:def 12 :: thesis: for b1 being Element of the carrier of K holds (FunctionalFAF (LQForm f),A) . (b1 * w) = b1 * ((FunctionalFAF (LQForm f),A) . w)
let r be Scalar of ; :: thesis: (FunctionalFAF (LQForm f),A) . (r * w) = r * ((FunctionalFAF (LQForm f),A) . w)
thus (FunctionalFAF (LQForm f),A) . (r * w) = (LQForm f) . A,(r * w) by Th9
.= f . v,(r * w) by A2, Def21
.= r * (f . v,w) by Th33
.= r * ((LQForm f) . A,w) by A2, Def21
.= r * ((FunctionalFAF (LQForm f),A) . w) by Th9 ; :: thesis: verum