A new iterative algorithm for comprehensive Gröbner systems
摘要
A comprehensive Gröbner system for a parametric ideal I in K(A)[X] represents the collection of all Gröbner bases of the ideals I′ in K[X] obtained as the values of the parameters A vary in K. The recent algorithms for computing them consider the corresponding ideal J in K[A, X], and are based on stability of Gröbner bases of ideals under specializations of the parameters A. Starting from a Gröbner basis of J, the computation splits recursively depending on the vanishing of the evaluation of some “coefficients” in K[A]. In this paper, taking inspiration from the algorithm described by Nabeshima, we create a new iterative algorithm to compute comprehensive Gröbner systems. We show how we keep track of the sub-cases to be considered, and how we avoid some redundant computation branches using “comparatively-cheap” ideal-membership tests, instead of radical-membership tests.