theorem Th42: :: JORDAN6:42

for n being Nat
for P being Subset of (TOP-REAL n)
for p1, p2 being Point of (TOP-REAL n) st P is_an_arc_of p1,p2 holds
ex p3 being Point of (TOP-REAL n) st
( p3 in P & p3 <> p1 & p3 <> p2 )