for P, Q, R, P9, Q9, R9 being POINT of BK-model-Plane
for p, q, r, p9, q9, r9 being Element of BK_model
for h being Element of SubGroupK-isometry
for N being invertible Matrix of 3,F_Real st h = homography N & between P,Q,R & P = p & Q = q & R = r & p9 = (homography N) . p & q9 = (homography N) . q & r9 = (homography N) . r & P9 = p9 & Q9 = q9 & R9 = r9 holds
between P9,Q9,R9