theorem Th2: :: GEOMTRAP:2

for V being RealLinearSpace
for u, u1, v, v1 being VECTOR of V
for p, q, p1, q1 being Element of (OASpace V) st p = u & q = v & p1 = u1 & q1 = v1 holds
( p,q // p1,q1 iff u,v // u1,v1 )