Singular Manual: areZeroElements

| #### D.15.23.36 areZeroElements Procedure from library `multigrading.lib` (see multigrading_lib). Usage: areZeroElements(D, [T]); intmat D, group T Purpose: For a integer matrix D, considered column-wise as a set of integer vecors representing the multidegree of some polynomial or vector this method checks whether all these multidegrees are contained in the grading group group (either set globally or given as an optional argument), i.e. if they all are zero in the multigrading. Example:
    LIB "multigrading.lib";
    ring r = 0,(x,y,z),dp;
    intmat S[2][3]=
    1,0,1,
    0,1,1;
    intmat L[2][1]=
    2,
    2;
    setBaseMultigrading(S,L);
    poly a = 1;
    poly b = xyz;
    ideal I = a, b;
    print(multiDeg(I));
    ==>      0     2
    ==>      0     2
    intmat m[5][2]=multiDeg(a),multiDeg(b); m=transpose(m);
    print(multiDeg(a));
    ==> 0,
    ==> 0
    print(multiDeg(b));
    ==> 2,
    ==> 2
    print(m);
    ==>      0     2     0     0     0
    ==>      0     2     0     0     0
    areZeroElements(m);
    ==> 1
    intmat LL[2][1]=
    1,
    -1;
    areZeroElements(m,LL);
    ==> 0

User manual for Singular version 4-1-1p4, 2018, generated by texi2html.