Singular Manual: ivDimCheck

| ##### 7.7.7.0. ivDimCheck Procedure from library `fpadim.lib` (see fpadim_lib). Usage: ivDimCheck(L,n); L a list of intmats, n an integer Return: int, 0 if the dimension is finite, or 1 otherwise Purpose: Decides, whether the K-dimension is finite or not Assume: - basering is a Letterplace ring. - All rows of each intmat correspond to a Letterplace monomial. Note: - n is the number of variables. Example:
    LIB "fpadim.lib";
    ring r = 0,(x,y),dp;
    def R = makeLetterplaceRing(5); // constructs a Letterplace ring
    R;
    ==> // coefficients: QQ
    ==> // number of vars : 10
    ==> //        block   1 : ordering a
    ==> //                  : names    x(1) y(1) x(2) y(2) x(3) y(3) x(4) y(4) x(\
       5) y(5)
    ==> //                  : weights     1    1    1    1    1    1    1    1   \
        1    1
    ==> //        block   2 : ordering dp
    ==> //                  : names    x(1) y(1)
    ==> //        block   3 : ordering dp
    ==> //                  : names    x(2) y(2)
    ==> //        block   4 : ordering dp
    ==> //                  : names    x(3) y(3)
    ==> //        block   5 : ordering dp
    ==> //                  : names    x(4) y(4)
    ==> //        block   6 : ordering dp
    ==> //                  : names    x(5) y(5)
    ==> //        block   7 : ordering C
    setring R; // sets basering to Letterplace ring
    //some intmats, which contain monomials in intvec representation as rows
    intmat I1 [2][2] = 1,1,2,2; intmat I2 [1][3]  = 1,2,1;
    intmat J1 [1][2] =  1,1; intmat J2 [2][3] = 2,1,2,1,2,1;
    print(I1);
    ==>      1     1
    ==>      2     2
    print(I2);
    ==>      1     2     1
    print(J1);
    ==>      1     1
    print(J2);
    ==>      2     1     2
    ==>      1     2     1
    list G = I1,I2;// ideal, which is already a Groebner basis
    list I = J1,J2; // ideal, which is already a Groebner basis and which
    ivDimCheck(G,2); // invokes the procedure, factor is of finite K-dimension
    ==> 0
    ivDimCheck(I,2); // invokes the procedure, factor is not of finite K-dimension
    ==> 1

User manual for Singular version 4-1-1, 2018, generated by texi2html.