let P be Subset of (TOP-REAL 2); for q being Point of (TOP-REAL 2) st P is being_simple_closed_curve & q in P holds
LE q,q,P
let q be Point of (TOP-REAL 2); ( P is being_simple_closed_curve & q in P implies LE q,q,P )
assume that
A1:
P is being_simple_closed_curve
and
A2:
q in P
; LE q,q,P
A3:
(Upper_Arc P) \/ (Lower_Arc P) = P
by A1, Def9;
A4:
Upper_Arc P is_an_arc_of W-min P, E-max P
by A1, Th65;
now per cases
( q in Upper_Arc P or ( q in Lower_Arc P & not q in Upper_Arc P ) )
by A2, A3, XBOOLE_0:def 3;
case A6:
(
q in Lower_Arc P & not
q in Upper_Arc P )
;
LE q,q,Pthen A7:
LE q,
q,
Lower_Arc P,
E-max P,
W-min P
by JORDAN5C:9;
q <> W-min P
by A4, A6, TOPREAL1:1;
hence
LE q,
q,
P
by A6, A7, Def10;
verum end; end; end;
hence
LE q,q,P
; verum