proposition: Lemma disjoint_setI0 A B : [disjoint A & B] -> A :&: B = set0.
proof: Proof. by rewrite -setI_eq0; move/eqP. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat div seq) mathcomp(choice fintype finfun bigop)