theorem Th12: :: JORDAN_A:12

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