|GREGORY S. SMITH, Department of Mathematics, University of California at Berkeley, Berkeley, California 94720-3840, USA|
|Computing global extension modules|
Let X be a projective scheme; let and be two coherent -modules. Given an integer m, we present an algorithm for computing the global extension module . In particular, this allows one to calculate the sheaf cohomology and to construct the sheaf corresponding to an element of the module . This algorithm can be implemented using only the computation of Gröbner bases and syzygies, and it has been implemented in the computer algebra system Macaulay2.