Section L13_1.
Context `{TnEQD:Tarski_neutral_dimensionless_with_decidable_point_equality}.
(** Pappus Desargues *)

Lemma col_cop_perp2__pars_bis : forall P A B C D, ~ Col A B P ->
Col C D P -> Coplanar A B C D -> Perp2 A B C D P -> Par_strict A B C D.