 intersection.  The duals of
	     these infinite projective resolutions are finitely generated
	     differential graded modules over a graded polynomial ring, so they can
	     be represented in the computer, and can be used to compute Ext
	     modules simultaneously in all homological degrees.  It is shown how to
	     write <i>Macaulay2</i> code to implement the construction, and how to use the
	     computer to determine invariants of modules over complete intersections
	     that are difficult to obt