adamc@34: signature S = sig
adamc@34:         type t
adamc@34:         val zero : t
adamc@34: end
adamc@34: structure S : S = struct
adamc@34:         type t = int
adamc@34:         val zero = 0
adamc@34: end
adamc@34: 
adamc@34: type t = S.t
adamc@34: val zero : t = S.zero