declare namespace gml = "http://www.opengis.net/gml";
      spatial:within(//gml:Polygon,
        <gml:Polygon srsName="osgb:BNG" xmlns:gml='http://www.opengis.net/gml'>
          <gml:outerBoundaryIs>
	    <gml:LinearRing>
	      <gml:coordinates>
	        278200,187600 278400,187600 278400,188000 278200,188000 278200,187600
	      </gml:coordinates>
	    </gml:LinearRing>
	  </gml:outerBoundaryIs>
        </gml:Polygon>
      )