Project(Extend(BGP( ?unit <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <https://w3id.org/jp-textbook/TeachingUnit> .
                    ?unit <https://w3id.org/jp-cos/cosItem> ?item),
               ?COUNT1,
               count(*) ),
        {?COUNT1})