(** The module [DecidableEqDep] collects equality properties for decidable set in [Type] *)
Module DecidableEqDep (M:DecidableType).
(** Invariance by Substitution of Reflexive Equality Proofs *)

Lemma eq_rect_eq :
forall (p:U) (Q:U -> Type) (x:Q p) (h:p = p), x = eq_rect p Q x p h.