for p1, p2, p3, p4, p5, p6 being Point of (TOP-REAL 2) st sin (angle (p1,p2,p3)) = sin (angle (p4,p5,p6)) & cos (angle (p1,p2,p3)) = cos (angle (p4,p5,p6)) holds
angle (p1,p2,p3) = angle (p4,p5,p6)