Add Field Kfth : FT.Definition Pp : params :=  Build_params 2 K.

(* Specifications: *)
Lemma tvcompare_eq v1 v2 : match tvcompare v1 v2 with Eq => v1 = v2 | _ => v1 <> v2 end.
Lemma tvcompare_refl v : tvcompare v v = Eq.