(** * Ordered type *)
From Stdlib Require OrderedType.
Module OT <: OrderedType.OrderedType with Definition t := string.
Definition t := string.
Definition eq s1 s2 := compare s1 s2 = Eq.
Definition lt s1 s2 := compare s1 s2 = Lt.

Lemma eq_refl (s : t) : eq s s.
End OT.