deffunc H1( Point of M, Point of M) -> Element of (vectgroup M) = vector $1,$2;
consider f being Function of [:the carrier of M,the carrier of M:],the carrier of (vectgroup M) such that
A1:
for p, q being Point of M holds f . p,q = H1(p,q)
from BINOP_1:sch 4();
take
f
; for p, q being Point of M holds f . p,q = vect p,q
for p, q being Point of M holds f . p,q = vect p,q
hence
for p, q being Point of M holds f . p,q = vect p,q
; verum