let p1, p2, p3, p4, p5, p6 be Point of (TOP-REAL 2); :: thesis: not angle p1,p2,p3 = (2 * (angle p4,p5,p6)) - (4 * PI )
assume A1: angle p1,p2,p3 = (2 * (angle p4,p5,p6)) - (4 * PI ) ; :: thesis: contradiction
( angle p4,p5,p6 < 2 * PI & angle p1,p2,p3 >= 0 ) by COMPLEX2:84;
then (angle p4,p5,p6) * 2 < (2 * PI ) * 2 by XREAL_1:70;
then ((angle p4,p5,p6) * 2) - (4 * PI ) < (4 * PI ) - (4 * PI ) by XREAL_1:11;
hence contradiction by A1, COMPLEX2:84; :: thesis: verum