let p1, p2, p3 be Point of (TOP-REAL 2); for a, b, r being real number st p1 in circle a,b,r & p2 in circle a,b,r & p3 in circle a,b,r & angle p1,p2,p3 = 0 & p1 <> p2 & p2 <> p3 holds
p1 = p3
let a, b, r be real number ; ( p1 in circle a,b,r & p2 in circle a,b,r & p3 in circle a,b,r & angle p1,p2,p3 = 0 & p1 <> p2 & p2 <> p3 implies p1 = p3 )
assume A1:
( p1 in circle a,b,r & p2 in circle a,b,r & p3 in circle a,b,r )
; ( not angle p1,p2,p3 = 0 or not p1 <> p2 or not p2 <> p3 or p1 = p3 )
assume A2:
angle p1,p2,p3 = 0
; ( not p1 <> p2 or not p2 <> p3 or p1 = p3 )
assume A3:
( p1 <> p2 & p2 <> p3 )
; p1 = p3
then A4:
( euc2cpx p1 <> euc2cpx p2 & euc2cpx p2 <> euc2cpx p3 )
by EUCLID_3:6;
assume A5:
p1 <> p3
; contradiction
then
euc2cpx p1 <> euc2cpx p3
by EUCLID_3:6;
then
( ( angle p2,p3,p1 = 0 & angle p3,p1,p2 = PI ) or ( angle p2,p3,p1 = PI & angle p3,p1,p2 = 0 ) )
by A2, A4, COMPLEX2:101;
hence
contradiction
by A1, A3, A5, Th35; verum