proposition: Lemma fgle_trans : transitive fgle.
proof: Proof. move=> D2 D1 D3 le12 le23; apply/fgleP=> z. by rewrite (@le_trans _ _ (coeff z D2)) //; apply/fgleP. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop order generic_quotient) mathcomp(ssralg ssrnum ssrint)