theorem Th10: :: AFF_4:10

for AS being AffinSpace
for a, b, a9, b9 being Element of AS
for M, N being Subset of AS st ( M // N or N // M ) & a in M & b in N & b9 in N & M <> N & ( a,b // a9,b9 or b,a // b9,a9 ) & a = a9 holds
b = b9