proposition: Lemma fproper0 A : (fset0 `<` A) = (A != fset0).
proof: Proof. by rewrite /fproper fsub0set fsubset0. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrnat eqtype ssrfun seq) mathcomp(choice path finset finfun fintype bigop)