LIB "sing.lib"; ring R=32003,(x,y,z),ds; // --------------------------------------- // hypersurface case (from series T[p,q,r]): int p,q,r = 3,3,4; poly f = x^p+y^q+z^r+xyz; tjurina(f); kbase(Tjurina(f)); // Tjurina number = 8 // --------------------------------------- // complete intersection case (from series P[k,l]): int k,l =3,2; ideal j=xy,x^k+y^l+z2; dim(std(j)); // Krull dimension size(minbase(j)); // minimal number of generators tjurina(j); // Tjurina number module T=Tjurina(j); kbase(T); // a sparse output of the k-basis of T1 print(kbase(T)); // columns of matrix are a k-basis of T1 // --------------------------------------- // general case (cone over rational normal curve of degree 4): ring r1=0,(x,y,z,u,v),ds; matrix m[2][4]=x,y,z,u,y,z,u,v; ideal i=minor(m,2); // 2x2 minors of matrix m module M=T1(i); // a presentation matrix of T1 vdim(M); // Tjurina number hilb(M); // display of both Hilbert series intvec v1=hilb(M,1); // first Hilbert series as intvec intvec v2=hilb(M,2); // second Hilbert series as intvec v1; v2; v1[3]; // 3-rd coefficient of the 1-st Hilbert series module N=T2(i); LIB "tst.lib";tst_status(1);$