proposition: Lemma axiom_two_points_on_line : forall l, { A : Tpoint & { B | IncidentL B l /\ IncidentL A l /\ A <> B}}.
proof: Proof. intros. exists (P1 l). exists (P2 l). unfold IncidentL. repeat split;Col. exact (Cond l). Qed.
imports: Morphisms GeoCoq.Axioms.hilbert_axioms GeoCoq.Axioms.parallel_postulates GeoCoq.Meta_theory.Parallel_postulates.tarski_playfair GeoCoq.Meta_theory.Parallel_postulates.SPP_ID GeoCoq.Meta_theory.Dimension_axioms.upper_dim_3 GeoCoq.Meta_theory.Parallel_postulates.parallel_postulates GeoCoq.Utils.triples