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 11 :: 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 VECTSP10:22;
let w, t be Vector of W; :: according to VECTSP_1:def 19 :: 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 Th8
.= f . (v,(w + t)) by A1, Def20
.= (f . (v,w)) + (f . (v,t)) by Th27
.= ((LQForm f) . (A,w)) + (f . (v,t)) by A1, Def20
.= ((LQForm f) . (A,w)) + ((LQForm f) . (A,t)) by A1, Def20
.= ((FunctionalFAF ((LQForm f),A)) . w) + ((LQForm f) . (A,t)) by Th8
.= ((FunctionalFAF ((LQForm f),A)) . w) + ((FunctionalFAF ((LQForm f),A)) . t) by Th8 ; :: thesis: verum
end;
let A be Vector of (VectQuot (V,(LKer f))); :: according to BILINEAR:def 13 :: 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 VECTSP10:22;
let w be Vector of W; :: according to HAHNBAN1:def 8 :: 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 Th8
.= f . (v,(r * w)) by A2, Def20
.= r * (f . (v,w)) by Th32
.= r * ((LQForm f) . (A,w)) by A2, Def20
.= r * ((FunctionalFAF ((LQForm f),A)) . w) by Th8 ; :: thesis: verum