let p1, p2, p3, p4, p5, p6 be Point of (TOP-REAL 2); not angle p1,p2,p3 = (2 * (angle p4,p5,p6)) + (4 * PI )
angle p4,p5,p6 >= 0
by COMPLEX2:84;
then
( 4 * PI >= 2 * PI & ((angle p4,p5,p6) * 2) + (4 * PI ) >= 0 + (4 * PI ) )
by XREAL_1:9, XREAL_1:66;
then A1:
((angle p4,p5,p6) * 2) + (4 * PI ) >= 2 * PI
by XXREAL_0:2;
assume
angle p1,p2,p3 = (2 * (angle p4,p5,p6)) + (4 * PI )
; contradiction
hence
contradiction
by A1, COMPLEX2:84; verum