proposition: Lemma oner_neqm1: 1 != -1 :> R.
proof: Proof. rewrite -addr_eq0 lt0r_neq0 ?addr_gt0 ?ltr01 //. 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.Meta_theory.Models.POF_to_Tarski GeoCoq.Meta_theory.Counter_models.Planar.independence