theorem Th13: :: HESSENBE:13

for PCPP being CollProjectiveSpace
for p1, p2, p3, q1, q2 being Element of PCPP st not p1,p2,q1 are_collinear & p1,p2,p3 are_collinear & q1,q2,p1 are_collinear & p1 <> p3 & p1 <> q2 holds
not p3,p1,q2 are_collinear