Section T10_1.
Context `{TnEQD:Tarski_neutral_dimensionless_with_decidable_point_equality}.

Lemma cop_image_in2__col : forall A B P P' Q Q' M,
Coplanar A B P Q -> ReflectL_at M P P' A B -> ReflectL_at M Q Q' A B ->
Col M P Q.