proposition: Lemma parP a b c d : par a b c d <-> Par (@Point R) (@bet' R) a b c d.
proof: Proof. split; move=> [?|[? [? [? ?]]]]; try (by left; apply par_strictP); right; repeat (split=> //); by apply colP. Qed.
imports: mathcomp.ssreflect.ssreflect mathcomp(ssrbool ssrfun ssrnat eqtype choice seq) mathcomp(fintype finset finfun bigop order) mathcomp(ssralg ssrnum path generic_quotient matrix mxalgebra) mathcomp(zmodp) GeoCoq.Axioms.gupta_inspired_variant_axioms GeoCoq.Tactics.Coinc.tactics_axioms GeoCoq.Tactics.Coinc.ColR GeoCoq.Meta_theory.Models.POF_to_Tarski GeoCoq.Meta_theory.Counter_models.Planar.independence