:- use_module(library(semweb/rdfa)).rdf(S,P,O)
triples extracted from
Input. Input is either a stream, a file name, a
URL referencing a file name or a URL that is valid for http_open/3. Options
are passed to open/4, http_open/3
and xml_rdfa/3. If no base is
provided in Options, a base is deduced from Input.