End MSupp.
Section MSetTheory.
Context {K : choiceType}.
Implicit Types (a b c : K) (A B C D : {mset K}) (s : seq K).

(* Specifications: *)
Lemma msetP {A B} : A =1 B <-> A = B.
Lemma count_mem_mset a A : count_mem a A = A a.
Lemma perm_undup_mset A : perm_eq (undup A) (finsupp A).
Section big_com.