Section T8_4.
Context `{TnEQD:Tarski_neutral_dimensionless_with_decidable_point_equality}.

Lemma midpoint_existence_aux : forall A B P Q T,
A<>B -> Perp A B Q B -> Perp A B P A ->
Col A B T -> Bet Q T P -> Le A P B Q ->
exists X : Tpoint, Midpoint X A B.