proposition: Lemma NoDupA_eqk_eqke l : NoDupA eqk l -> NoDupA eqke l.
proof: Proof. apply NoDupA_incl. now destruct 1. Qed.
imports: Coq(Bool Equalities Orders OrdersFacts OrdersLists) Coq(Morphisms Permutation SetoidPermutation) MMaps(Utils Comparisons Interface)