val to_int : ('digits, 'word) t -> intval to_string : ('digits, 'word) t -> stringval equal : ('digits, 'word) t -> ('digits, 'word) t -> boolval succ : ('digits, 'word) t -> ('digits, 'word) tval pred : ('digits, 'word) t -> ('digits, 'word) tval add : ('digits, 'word) t -> ('digits, 'word) t -> ('digits, 'word) tval sub : ('digits, 'word) t -> ('digits, 'word) t -> ('digits, 'word) tval rem : ('digits, 'word) t -> ('digits, 'word) t -> ('digits, 'word) tval logxor : ('digits, 'word) t -> ('digits, 'word) t -> ('digits, 'word) tval rotL : ('digits, 'word) t -> ('digits, 'word) t -> ('digits, 'word) t