let P be Subset of (TOP-REAL 2); for p1, p2, q being Point of (TOP-REAL 2) st P is_an_arc_of p1,p2 & LE q,p1,P,p1,p2 holds
q = p1
let p1, p2, q be Point of (TOP-REAL 2); ( P is_an_arc_of p1,p2 & LE q,p1,P,p1,p2 implies q = p1 )
assume that
A1:
P is_an_arc_of p1,p2
and
A2:
LE q,p1,P,p1,p2
; q = p1
q in P
by A2;
then
LE p1,q,P,p1,p2
by A1, JORDAN5C:10;
hence
q = p1
by A1, A2, JORDAN5C:12; verum