proposition: Lemma min_L: forall x y, min x y = x <-> x <= y.
proof: Proof. split;intros. destruct H. apply Nat.le_min_r. apply min_l;trivial. Qed.
imports: Coq(List) JML(Stack) Coq(ListSet) Coq(Bool) Coq(ZArith) Coq(Relation_Operators) JML(ListHelpers) Coq(Classical)