proposition: Lemma ltR_trans x y z : x < y -> y < z -> x < z.
proof: Proof. by move/ltRW; apply: leR_lt_trans. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div order) mathcomp(ssralg ssrnum ssrint rat intdiv) Coq(Morphisms Setoid) fourcolor(real realsyntax)