---
title: "Magma V2.21-9 Patch Notes"
canonical: "https://docs.magma-maths.org/patchnotes/2.21-9.html"
source: "https://docs.magma-maths.org/patchnotes/2.21-9.md"
---

<a id="magma-v2-21-9-patch-notes"></a>
# Magma V2.21-9 Patch Notes

## ATLAS database

- The matrix representation of U5(2) of dimension 55 over GF(11) was incorrect and has now been fixed.
- The intrinsics [`ATLASGroupNames`](../FiniteGroups/DatabasesOfGroups/ATLAS-database.md#function-atlasgroupnames) and `AtlasGroupnames` now correctly indicate that their return type is `SetIndx`, not `SeqEnum`.
- A minor regression: The first two matrix representations of E6(2) have been swapped.  Similarly, the two permutation representations of O8-(3).2_3 have been swapped.

## Algebraic Function Fields

- Error checking has been improved in `Automorphisms` of an algebraic function field over a given coefficient field. This intrinsic is currently only for function fields whose constant field is the rational field.

## Matrices

- A precision problem with p-adic determinants has been fixed. Reported by C. Birkbeck.

## Modules

- The functions `Representation` and [`Submodules`](../RepresentationTheory/ModulesOverAnAlgebraAndGroupRepresentations/submodule-lattice.md#function-repthy-submodules) now work for G-modules of dimension zero.  Problem reported by G. Tornaria.

## Modules over Dedekind Domains

- Compatibility of modules over Dedekind domains has been improved. This, in particular, allows more flexibility in the combination of inputs to `+` and `meet`.

## Number Field Sieve

- The [`OptimalSkewness`](../BasicRings/Integers/nfs.md#function-optimalskewness-rngmpolelt) intrinsic now checks that its input is defined over the integers.

## Polynomials

- A bug that could cause crashes when computing the roots of a polynomial over a Laurent series algebra has been fixed.
- A crash in factorization of polynomials over a chain of function fields in characteristic zero has been fixed.
- A crash in multivariate GCD has been fixed.  Reported by R. Lewis.

## Quadratic Fields

- The `Kernel` of a matrix over an order of a quadratic field which is also a Euclidean ring has been fixed.

## Series

- The `IsPower` intrinsic for series has been improved to consider scaling by a leading coefficient that is not 1. Reported by M. Stoll.

## System

- A bug that could cause [`require`](../MagmaLanguage/FunctionsProceduresAndPackages/package.md#literal-literal-require-require-condition-print-args) directives to report the wrong error location has been fixed.