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Magma V2.23-4 Patch Notes

Patch release for Magma V2.23-4. Updated areas: Algebras, Commutative Algebra, Elliptic Curves, Galois Groups, Groebner Bases and 9 more.

14 areas

Algebras

  • A missing error check for JacobsonRadical for algebras over non-supported rings has been added.

Commutative Algebra

  • A crash in SyzygyModule for certain types of polynomial rings defined over the rational field has been fixed. Reported by M. Reid.

  • A subtle bug in PrimaryDecomposition (occurring very rarely for ideals in characteristic zero) has been fixed.

Elliptic Curves

  • A (very rare) infinite recursion in the point counting algorithm when used with ellpitic curves defined over non-default finite fields has been fixed. This led to problems with the Order function too which have been fixed. Reported by C. Cheng.

Galois Groups

  • Extra printing has been removed from the computation of Galois groups of reducible polynomials. Reported by D. Krumm.

Groebner Bases

  • A non-trivial slow down in the dense F4 algorithm over GF(2) has been fixed. Further improvements have been added at the same time.

Groups

  • A crash in unipotent matrix groups has been fixed. Bug reported by E. O’Brien.

  • A new version of the function ClassTwo to count p-class 2 p-groups is distributed which incorporates improvements by Michael Vaughan-Lee and is much faster than the original.

Integer Residue Class Rings

  • A crash in the preimage application of the multiplicative map for large residue rings has been fixed. This preimage computation has also been considerably sped up.

Invariant Theory

Local Rings

  • A fix has been made to the Factorization of polynomials over local rings. Reported by E. Thomé.

Matrices

  • The base algorithm for matrix echelonisation in moderately small dimension has been improved for matrices over GF(4).

  • A crash with EchelonForm over a ring with zero divisors has been changed to give an error concerning non-invertibility of elements.

  • A crash in Solution for matrices defined over multivariate polynomial rings has been fixed.

  • The base algorithm for matrix multiplication in moderately small dimension has been improved for matrices over GF(4), GF(5) and GF(7).

  • The base algorithm for matrix echelonisation in moderately small dimension has been improved for matrices over GF(4).

Modular Arithmetic Geometry

Polynomial Rings

  • A leak in bivariate multiplication over rings with elements stored in blocks has been fixed. Reported by D. Barth.

  • A bug in IsPrime and IsIrreducible for polynomials over the integers has been fixed. Reported by J. Klueners.

  • A crash in multiplication of polynomials defined over matrices has been fixed.

Real and Complex Fields

  • A hang and some accuracy errors in complex root finding have been fixed. Reported by J. Klueners.

Series Rings

  • A fix has been made to the Roots computation for polynomials over series rings whose degree is the characteristic of the coefficient ring. Reported by J. Tuitman.

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