#### D.4.19.9 intersectionValRings

Procedure from library `normaliz.lib` (see normaliz_lib).

Usage:
  intersectionValRings(intmat V, intvec grading);

Return:
  The function returns a monomial ideal, to be considered as the list of monomials generating as an algebra over the coefficient field.

Background:
  A discrete monomial valuation on is determined by the values of the indeterminates. This function computes the subalgebra for several such valuations , . It needs the matrix as its input.

  The function returns the ideal given by the input matrix V if one of the options `supp`, `triang`, `volume`, or `hseries` has been activated. However, in this case some numerical invariants are computed, and some other data may be contained in files that you can read into Singular (see showNuminvs, exportNuminvs).

Example:

    LIB "normaliz.lib";
    ring R=0,(x,y,z,w),dp;
    intmat V0[2][4]=0,1,2,3, -1,1,2,1;
    intersectionValRings(V0);
    ==> _[1]=y
    ==> _[2]=z
    ==> _[3]=w
    ==> _[4]=xy
    ==> _[5]=x2z
    ==> _[6]=xw
    ==> _[7]=xz

See also: diagInvariants; finiteDiagInvariants; intersectionValRingIdeals; torusInvariants.

User manual for Singular version 4-0-3, 2016, generated by texi2html.