proposition: Lemma gtR_neq x y : x > y -> x != y.
proof: Proof. by move=> gtxy []. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div order) mathcomp(ssralg ssrnum ssrint rat intdiv) Coq(Morphisms Setoid) fourcolor(real realsyntax)