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PseudomonomialPrimaryDecomposition :: PseudomonomialPrimaryDecomposition

PseudomonomialPrimaryDecomposition -- primary decomposition of a square free pseudomonomial ideal


A pseudomonomial is a polynomial in K[x1,x2,...,xn] that can be written as a product of factors of the form (xi-ai)^ni, where ai is 0 or 1. The xi's in the product should be distinct. A square free pseudomonomial ideal is an ideal generated by pseudomonomials such that each ni=1.

This package finds the primary decomposition of square free pseudomonomial ideals. It also determines if an ideal is a pseudomonomial ideal.

For example, x1^2*(x3-1) is a pseudomonomial, but not square free. The polynomial x1*(x3-1) is a square free pseudomonomial. The ideal ideal(x1*(x3-1),(x1-1)*(x2-1)*x4,x1*x2*x3,(x1-1)*x2*(x5-1)) is a square free pseudomonomial ideal.

i1 : R = ZZ/2[x1,x2,x3,x4,x5];
i2 : I = ideal(x1*(x3-1),(x1-1)*(x2-1)*x4,x1*x2*x3,(x1-1)*x2*(x5-1));

o2 : Ideal of R
i3 : isSquarefreePseudomonomialIdeal I

o3 = true
i4 : C = primaryDecompositionPseudomonomial I

o4 = {ideal (x5 + 1, x1, x2 + 1), ideal (x2, x3 + 1, x1 + 1), ideal (x1, x4,
     x2), ideal (x1, x4, x5 + 1), ideal (x3 + 1, x4, x2)}

o4 : List
i5 : intersect C == I

o5 = true



This documentation describes version 0.3 of PseudomonomialPrimaryDecomposition.

Source code

The source code from which this documentation is derived is in the file PseudomonomialPrimaryDecomposition.m2.


For the programmer

The object PseudomonomialPrimaryDecomposition is a package.