Section TCP_tarski.
Context `{TnEQD:Tarski_neutral_dimensionless_with_decidable_point_equality}.

Lemma impossible_two_sides_not_col : forall A B C D T Y,
A <> D ->
B <> D ->
C <> D ->
D <> T ->
~ Col A B C ->
Bet A D T ->
~ Col B C T ->
Bet B D C ->
Bet B Y T ->
~ Col A C Y.