`sig
type t
val validate_positive : Comparable_intf.With_zero.t Validate.check
val validate_non_negative : Comparable_intf.With_zero.t Validate.check
val validate_negative : Comparable_intf.With_zero.t Validate.check
val validate_non_positive : Comparable_intf.With_zero.t Validate.check
val is_positive : Comparable_intf.With_zero.t -> bool
val is_non_negative : Comparable_intf.With_zero.t -> bool
val is_negative : Comparable_intf.With_zero.t -> bool
val is_non_positive : Comparable_intf.With_zero.t -> bool
end`