---
title: "Magma V2.23-4 Patch Notes"
canonical: "https://docs.magma-maths.org/patchnotes/2.23-4.html"
source: "https://docs.magma-maths.org/patchnotes/2.23-4.md"
---

<a id="magma-v2-23-4-patch-notes"></a>
# Magma V2.23-4 Patch Notes

## 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`](../FiniteGroups/FiniteSolubleGroups/p-groups.md#function-classtwo-rngintelt-rngintelt) 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

- A crash in `FundamentalInvariants` for invariant rings over inexact rings has been fixed.

## 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

- A crash in [`DualHeckeOperator`](../ModularArithmeticGeometry/ModularSymbols/operators.md#function-dualheckeoperator-modsym-rngintelt) has been fixed.  Reported by D-A. Guiraud.

## 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.