let V be RealLinearSpace; for w, y being VECTOR of V st Gen w,y holds
for p, q, r being Element of (AMSpace (V,w,y)) holds p,q _|_ r,r
let w, y be VECTOR of V; ( Gen w,y implies for p, q, r being Element of (AMSpace (V,w,y)) holds p,q _|_ r,r )
assume A1:
Gen w,y
; for p, q, r being Element of (AMSpace (V,w,y)) holds p,q _|_ r,r
let p, q, r be Element of (AMSpace (V,w,y)); p,q _|_ r,r
reconsider u = p, v = q, u1 = r as Element of V ;
u1 - u1 = 0. V
by RLVECT_1:15;
then
v - u,u1 - u1 are_Ort_wrt w,y
by A1, Th5;
then
u,v,u1,u1 are_Ort_wrt w,y
;
hence
p,q _|_ r,r
by Th21; verum