let V be RealLinearSpace; :: thesis: for w, y being VECTOR of V
for p, p1, q, q1 being Element of (AMSpace (V,w,y)) st p,q _|_ p1,q1 holds
p1,q1 _|_ p,q
let w, y be VECTOR of V; :: thesis: for p, p1, q, q1 being Element of (AMSpace (V,w,y)) st p,q _|_ p1,q1 holds
p1,q1 _|_ p,q
let p, p1, q, q1 be Element of (AMSpace (V,w,y)); :: thesis: ( p,q _|_ p1,q1 implies p1,q1 _|_ p,q )
reconsider u = p, v = q, u1 = p1, v1 = q1 as Element of V ;
assume p,q _|_ p1,q1 ; :: thesis: p1,q1 _|_ p,q
then u,v,u1,v1 are_Ort_wrt w,y by Th21;
then v - u,v1 - u1 are_Ort_wrt w,y ;
then v1 - u1,v - u are_Ort_wrt w,y ;
then u1,v1,u,v are_Ort_wrt w,y ;
hence p1,q1 _|_ p,q by Th21; :: thesis: verum