proposition: Lemma row2_eq0_nD (a b : R) : (row_mx (row2 a b) (@const_mx R 1 (n.+2) 0) == 0) = ((a == 0) && (b == 0)).
proof: Proof. by rewrite row_mx_eq0 eqxx andbT row2_eq0. Qed.
imports: mathcomp.ssreflect.ssreflect mathcomp(ssrbool ssrfun ssrnat eqtype seq order) mathcomp(fintype bigop) mathcomp(ssralg ssrnum matrix) mathcomp(zmodp) GeoCoq.Axioms.tarski_axioms GeoCoq.Axioms.gupta_inspired_variant_axioms GeoCoq.Meta_theory.Models.gupta_inspired_to_tarski GeoCoq.Meta_theory.Counter_models.coplanarity GeoCoq.Meta_theory.Parallel_postulates.parallel_postulates GeoCoq.Tarski_dev.Ch12_parallel_inter_dec