T : sig ... endval validate_positive : t Base.Validate.checkval validate_non_negative : t Base.Validate.checkval validate_negative : t Base.Validate.checkval validate_non_positive : t Base.Validate.checkval is_positive : t ‑> boolval is_non_negative : t ‑> boolval is_negative : t ‑> boolval is_non_positive : t ‑> boolval sign : t ‑> Base__.Sign0.tReturns Neg, Zero, or Pos in a way consistent with the above functions.