val equal : t -> t -> boolval of_string : string -> (t, [ `Msg of string ]) resultval of_string_exn : string -> tval to_string : t -> stringval extension : string -> string -> (t, [ `Msg of string ]) resultval atom : string -> (atom, [ `Msg of string ]) resultval atom_exn : string -> atommodule Peano : sig ... endval unsafe_domain_of_list_exn : string list -> tval make : 'a w -> 'a -> (t, [ `Msg of string ]) result