def skos_hierarchical(rdf, narrower=True):
if narrower:<EOL><INDENT>for s, o in rdf.subject_objects(SKOS.broader):<EOL><INDENT>rdf.add((o, SKOS.narrower, s))<EOL><DEDENT><DEDENT>for s, o in rdf.subject_objects(SKOS.narrower):<EOL><INDENT>rdf.add((o, SKOS.broader, s))<EOL>if not narrower:<EOL><INDENT>rdf.remove((s, SKOS.narrower, o))<EOL><DEDENT><DEDENT>
Infer skos:broader/skos:narrower (S25) but only keep skos:narrower on request.

    :param bool narrower: If set to False, skos:narrower will not be added,
        but rather removed.