Groebner.jl is a package for fast and generic Gröbner bases computations based on Faugère's F4 algorithm written in Julia.
To install Groebner.jl, run the following in the Julia REPL:
using Pkg; Pkg.add("Groebner")
See Interface for a description of all exported functions. For a quick introduction to Groebner bases we refer to Tutorials. Meanwhile, below are simple examples.
Currently, polynomials from AbstractAlgebra.jl, DynamicPolynomials.jl, and Nemo.jl are supported as input.
First, import AbstractAlgebra.jl. Then, we can create an array of polynomials over a finite field
using AbstractAlgebra
R, (x, y, z) = polynomial_ring(GF(2^31 - 1), ["x", "y", "z"])
polys = [x^2 + y + z, x*y + z];
and compute the Groebner basis with the groebner
command
using Groebner
basis = groebner(polys)
4-element Vector{AbstractAlgebra.Generic.MPoly{AbstractAlgebra.GFElem{Int64}}}:
y^3 + y^2*z + z^2
x*z + 2147483646*y^2 + 2147483646*y*z
x*y + z
x^2 + y + z
We can check if a set of polynomials forms a basis
isgroebner(basis)
true
Groebner.jl also provides several monomial orderings. For example, we can eliminate z
from the above system:
ordering = Lex(z) * DegRevLex(x, y) # z > x, y
groebner(polys, ordering=ordering)
2-element Vector{AbstractAlgebra.Generic.MPoly{AbstractAlgebra.GFElem{Int64}}}:
x^2 + 2147483646*x*y + y
x*y + z
You can find more information on monomial orderings in Groebner.jl in Monomial Orderings.
We will compute the basis of the noon-2
system
using DynamicPolynomials
@polyvar x1 x2
system = [10*x1*x2^2 - 11*x1 + 10,
10*x1^2*x2 - 11*x2 + 10]
groebner(system)
3-element Vector{DynamicPolynomials.Polynomial{DynamicPolynomials.Commutative{DynamicPolynomials.CreationOrder}, MultivariatePolynomials.Graded{MultivariatePolynomials.LexOrder}, Int64}}:
10x2 - 10x1 - 11x2² + 11x1²
110 - 121x2 - 100x2² + 100x1x2 + 110x2³
10 - 11x1 + 10x1x2²
This library is maintained by Alexander Demin (asdemin_2@edu.hse.ru).
We would like to acknowledge the developers of the msolve library (https://msolve.lip6.fr/), as several components of Groebner.jl were adapted from msolve. In our F4 implementation, we adapt and adjust the code of monomial hashtable, critical pair handling and symbolic preprocessing, and linear algebra from msolve. The source code of msolve is available at https://github.com/algebraic-solving/msolve.
We thank Vladimir Kuznetsov for helpful discussions and providing the sources of his F4 implementation.
We are grateful to The Max Planck Institute for Informatics and The MAX team at l'X for providing computational resources.