type domain_item =
| Id of (string * string option) (* literal, opt. uri *)
| Symbol of string * (string option * string) option (* literal, opt. (uri,interp.) *)
| Num of (string option * string) option (* opt. uri, interpretation *)
type domain_item =
| Id of (string * string option) (* literal, opt. uri *)
| Symbol of string * (string option * string) option (* literal, opt. (uri,interp.) *)
| Num of (string option * string) option (* opt. uri, interpretation *)