For subschemes X,Y of ℙn1x...xℙnm this command computes the dimension X part of the Segre class s(X,Y) of X in Y as a class in the Chow ring of ℙn1x...xℙnm. This is faster than computing the entire Segre class.
R = makeProductRing({2,2}) |
x = gens(R) |
Y = ideal(random({2,2},R)); |
X = Y+ideal(x_0*x_3+x_1*x_4); |
A = makeChowRing(R) |
time s = segreDimX(X,Y,A) |
time segre(X,Y,A) |