Section T10_1.
Context `{TnEQD:Tarski_neutral_dimensionless_with_decidable_point_equality}.

Lemma image_preserves_col : forall A B C A' B' C' X Y,
ReflectL A A' X Y -> ReflectL B B' X Y -> ReflectL C C' X Y ->
Col A B C ->
Col A' B' C'.