def skos_symmetric_mappings(rdf, related=True):
for s, o in rdf.subject_objects(SKOS.relatedMatch):<EOL><INDENT>rdf.add((o, SKOS.relatedMatch, s))<EOL>if related:<EOL><INDENT>rdf.add((s, SKOS.related, o))<EOL>rdf.add((o, SKOS.related, s))<EOL><DEDENT><DEDENT>for s, o in rdf.subject_objects(SKOS.closeMatch):<EOL><INDENT>rdf.add((o, SKOS.closeMatch, s))<EOL><DEDENT>for s, o in rdf.subject_objects(SKOS.exactMatch):<EOL><INDENT>rdf.add((o, SKOS.exactMatch, s))<EOL><DEDENT>
Ensure that the symmetric mapping properties (skos:relatedMatch,
    skos:closeMatch and skos:exactMatch) are stated in both directions (S44).

    :param bool related: Add the skos:related super-property for all
        skos:relatedMatch relations (S41).