theorem Th9: :: ANALMETR:9

for V being RealLinearSpace
for u1, u2, v, w, y being VECTOR of V st Gen w,y & v,u1 are_Ort_wrt w,y & v,u2 are_Ort_wrt w,y & v <> 0. V holds
ex a, b being Real st
( a * u1 = b * u2 & ( a <> 0 or b <> 0 ) )