Singular Manual: lpSickleDim

| ##### 7.7.7.0. lpSickleDim Procedure from library `fpadim.lib` (see fpadim_lib). Usage: lpSickleDim(G[,degbound,n]); G an ideal, degbound, n optional integers Return: list Purpose: Computing the K-dimension and the mistletoes Assume: - basering is a Letterplace ring. G is a Letterplace ideal. - if you specify a different degree bound degbound, degbound <= attrib(basering,uptodeg) should hold. Note: - If L is the list returned, then L[1] is an integer, the K-dimension, L[2] is an ideal, the mistletoes. - If degbound is set, there will be a degree bound added. 0 means no degree bound. Default: attrib(basering,uptodeg). - n is the number of variables, which can be set to a different number. Default: attrib(basering, lV). - If the K-dimension is known to be infinite, a degree bound is needed Example:
    LIB "fpadim.lib";
    ring r = 0,(x,y),dp;
    def R = makeLetterplaceRing(5); // constructs a Letterplace ring
    setring R; // sets basering to Letterplace ring
    ideal G = x(1)*x(2), y(1)*y(2),x(1)*y(2)*x(3); // ideal G contains a
    //Groebner basis
    lpSickleDim(G); // invokes the procedure with ring parameters
    ==> [1]:
    ==>    6
    ==> [2]:
    ==>    _[1]=x(1)*y(2)
    ==>    _[2]=y(1)*x(2)*y(3)
    // the factor algebra is finite, so the degree bound given by the Letterplace
    // ring is not necessary
    lpSickleDim(G,0); // procedure without any degree bound
    ==> [1]:
    ==>    6
    ==> [2]:
    ==>    _[1]=x(1)*y(2)
    ==>    _[2]=y(1)*x(2)*y(3)

User manual for Singular version 4-0-2, 2015, generated by texi2html.