proposition: Lemma colH_IncidL__IncidL : forall A B C l, A<>B -> IncidL A l -> IncidL B l -> ColH A B C -> IncidL C l.
proof: Proof. intros. elim H2. intros. spliter. assert (EqL l x) by (eauto using line_uniqueness). rewrite H6 in *. assumption. Qed.
imports: Setoid Coq.Classes.Morphisms Coq.Classes.Morphisms_Prop GeoCoq.Axioms.gupta_inspired_variant_axioms GeoCoq.Meta_theory.Models.gupta_inspired_to_tarski GeoCoq.Tactics.Coinc.tactics_axioms GeoCoq.Tactics.Coinc.ColR GeoCoq.Meta_theory.Dimension_axioms.upper_dim_3 GeoCoq.Meta_theory.Parallel_postulates.parallel_postulates GeoCoq.Axioms.hilbert_axioms