proposition: Lemma minset_eq P1 P2 A : P1 =1 P2 -> minset P1 A = minset P2 A.
proof: Proof. by move=> eP12; apply: eq_forallb => B; rewrite eP12. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat div seq) mathcomp(choice fintype finfun bigop)