let V, W be non empty ModuleStr over F_Complex ; (NulForm (V,W)) *' = NulForm (V,W)
set f = NulForm (V,W);
now for v being Vector of V
for w being Vector of W holds ((NulForm (V,W)) *') . (v,w) = (NulForm (V,W)) . (v,w)let v be
Vector of
V;
for w being Vector of W holds ((NulForm (V,W)) *') . (v,w) = (NulForm (V,W)) . (v,w)let w be
Vector of
W;
((NulForm (V,W)) *') . (v,w) = (NulForm (V,W)) . (v,w)thus ((NulForm (V,W)) *') . (
v,
w) =
((NulForm (V,W)) . (v,w)) *'
by Def8
.=
0. F_Complex
by COMPLFLD:47, FUNCOP_1:70
.=
(NulForm (V,W)) . (
v,
w)
by FUNCOP_1:70
;
verum end;
hence
(NulForm (V,W)) *' = NulForm (V,W)
; verum