SELECT r.x,r.comp
	FROM sparqltable (SELECT ?x  ?commpr ?comp ?costopr
		WHERE{
			?prog rdf:type 'Progetto'.
			?prog :numIdent ?x.
			?prog :costo?costopr.
			?commpr rdf:type 'Committente'.
                                                                                        (?commpr :commessa ?prog) :compenso ?comp.
})r
GROUP BY  r.x,r.costopr
HAVING r.costopr<SUM(r.comp)