proposition: Lemma le_ffix_order (x y : T) : y \in iterF (ffix_order x) -> ffix_order y <= ffix_order x.
proof: Proof. exact: ffix_order_small. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrnat eqtype ssrfun seq) mathcomp(choice path finset finfun fintype bigop)