Section T10.
Context `{TnEQD:Tarski_neutral_dimensionless_with_decidable_point_equality}.
Goal forall A B C D, ~ Coplanar D C B A -> ~ Coplanar A B C D.

Lemma midpoint_preserves_image : forall A B P P' Q Q' M,
A <> B -> Col A B M -> Reflect P P' A B ->
Midpoint M P Q -> Midpoint M P' Q' -> Reflect Q Q' A B.