theorem Th13:
for
C being
Simple_closed_curve for
p being
Point of
(TOP-REAL 2) st
LE p,
E-max C,
C holds
Segment (
p,
(W-min C),
C)
= (R_Segment ((Upper_Arc C),(W-min C),(E-max C),p)) \/ (L_Segment ((Lower_Arc C),(E-max C),(W-min C),(W-min C)))