For a subvariety X of ℙn1x...xℙnm and an irreducible subscheme Y of ℙn1x...xℙnm this command tests whether X is contained in the singular locus of the reduced scheme of Y (i.e. the singular locus of the variety defined by the radical of the ideal defining Y).
n=6 |
R = makeProductRing({n}) |
x=gens(R) |
m=matrix{for i from 0 to n-3 list x_i,for i from 0 to n-3 list (i+3)*x_(i+3),for i from 0 to n-3 list x_(i+2),for i from 0 to n-3 list x_(i)+(5+i)*x_(i+1)} |
C=ideal mingens(minors(3,m)); |
P=ideal(x_0,x_4,x_3,x_2,x_1) |
containedInSingularLocus(P,C) |