fact: Definition discrete X := forall x y : X, decidable (x=y).
imports: List Arith Bool Eqdep_dec Undecidability.Synthetic.Definitions Undecidability.Synthetic.ReducibilityFacts Undecidability.Synthetic.InformativeDefinitions Undecidability.Synthetic.InformativeReducibilityFacts Undecidability.Shared.Libs.DLW.Utils(utils_tac utils_list utils_nat finite) Undecidability.Shared.Libs.DLW.Vec(pos vec) Undecidability.FOL.TRAKHTENBROT(notations utils fol_ops)