|
D.15.24.4 symExt
Procedure from library tateProdCplxNegGrad.lib (see tateProdCplxNegGrad_lib).
- Usage:
- symExt(m); m matrix
- Purpose:
- computes differential R(M_0) -> R(M_1) for the module M over S corresponding to the linear presentation matrix m, however, in order to
get the result, m has to be fetched to the exterior algebra E
- Assume:
- m a matrix, linear presentation matrix over S; Note: also works for nonlinear matrices, but makes no sense to use it in this case
- Return:
- matrix B representing R(M_0) -> R(M_1)
- Note:
- output lives in S (not as in Macaulay2 in the ring E, to get the same result, just fetch the matrix to E)
Example:
| LIB "tateProdCplxNegGrad.lib";
intvec c = 1,2;
def (S,E) = productOfProjectiveSpaces(c);
setring(S);
matrix m[4][2] = x(0)(0), x(1)(0),x(0)(1),0,0,x(1)(1), 0,x(1)(2);
matrix A = symExt(m);
print(A);
setring(E);
print(fetch(S,A));
|
|