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7.10.3.5 lpGlDimBound

Procedure from library fpaprops.lib (see fpaprops_lib).

Usage:
lpGlDimBound(I); I an ideal

Return:
int, an upper bound for the global dimension, -1 means infinity

Purpose:
computing an upper bound for the global dimension

Assume:
- basering is a Letterplace ring, G is a reduced Groebner Basis

Note:
if I = LM(I), then the global dimension is equal the Gelfand Kirillov dimension if it is finite
Global dimension should be 0 for A/G = K and 1 for A/G = K<x1...xn>

Example:
 
LIB "fpaprops.lib";
ring r = 0,(x,y),dp;
def R = freeAlgebra(r, 5); // constructs a Letterplace ring
setring R; // sets basering to Letterplace ring
ideal G = x*x, y*y,x*y*x; // it is a monomial Groebner basis
lpGlDimBound(G);
==> 0
ideal H = y*x - x*y; H = std(H); // H is a Groebner basis
lpGlDimBound(H); // gl dim of K[x,y] is 2, as expected
==> 2