(* Gabriel Braun April 2013 *)
Require Export GeoCoq.Tarski_dev.Ch13_4_cos.
Require Export GeoCoq.Tarski_dev.Annexes.project.
Section Pappus_Pascal.
Context `{T2D:Tarski_2D}.
Context `{TE:@Tarski_euclidean Tn TnEQD}.

Lemma lcos_per_anga : forall O A P la lp a, Lcos lp la a -> la O A -> lp O P -> Per A P O -> a A O P.