Instance find_elt_compat A dom (m : t A dom) : Proper (X.eq ==> Logic.eq) (fun x => find x m).

Lemma from_elements_spec : forall A (l : list (key * A)), NoDupA (X.eq@@1)%signature l -> forall x v, find x (from_elements l) = Some v <-> InA (X.eq * eq)%signature (x, v) l.