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 cong_midpoint__image : forall A B X Y, Cong A X A Y -> Midpoint B X Y -> Reflect Y X A B.