proposition: Lemma leRq a x : x >= a <-> a <= x.
proof: Proof. by split=> [/gec_lt_trans | leax /leax]; last rewrite ltcE ltxx. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq order) mathcomp(ssralg ssrnum ssrint rat) fourcolor(real) Coq(Setoid Morphisms)