Notation eqke := (@eqke elt).Notation eqk := (@eqk elt).Instance eqk_equiv : Equivalence eqk.Instance eqke_equiv : Equivalence eqke.

Lemma InA_eqke_eqk : forall k1 k2 e1 e2 l, E.eq k1 k2 -> InA eqke (k1,e1) l -> InA eqk (k2,e2) l.