proposition: Lemma leR_trans x y z : x <= y -> y <= z -> x <= z.
proof: Proof. exact: (Real.le_transitive R). Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div order) mathcomp(ssralg ssrnum ssrint rat intdiv) Coq(Morphisms Setoid) fourcolor(real realsyntax)