(* Gabriel Braun April 2013 *)
Require Export GeoCoq.Tarski_dev.Ch12_parallel.
Section L13_1.
Context `{TnEQD:Tarski_neutral_dimensionless_with_decidable_point_equality}.
(** Pappus Desargues *)

Lemma per_lt : forall A B C, A <> B ->  C <> B -> Per A B C -> Lt A B A C /\ Lt C B A C.