theorem Th11: :: HESSENBE:11

for PCPP being CollProjectiveSpace
for p1, p2, q1, q2, q3 being Element of PCPP st not p1,p2,q1 are_collinear & p1,p2,q2 are_collinear & q1,q2,q3 are_collinear & q2 <> q3 holds
not p2,p1,q3 are_collinear