theorem
for
S being non
empty satisfying_Tarski-model satisfying_Lower_Dimension_Axiom TarskiGeometryStruct for
a,
b,
c,
d,
x,
p,
q being
POINT of
S st
c in Line (
a,
b) &
d in Line (
a,
b) &
a <> b &
c <> d holds
Line (
a,
b)
= Line (
c,
d)
by Prelim11;