---
title: "Magma V2.28-9 Patch Notes"
canonical: "https://docs.magma-maths.org/patchnotes/2.28-9.html"
source: "https://docs.magma-maths.org/patchnotes/2.28-9.md"
---

<a id="magma-v2-28-9-patch-notes"></a>
# Magma V2.28-9 Patch Notes

## Algebraic Function Fields

- [`RationalFunction`](../GlobalFields/AlgebraicFunctionFields/elements.md#function-rationalfunction-fldfungelt) for elements of non simple function fields now ensures the element has known coefficients rather than returning 0. Reported by F. Hess.
- Applying `Automorphisms` to elements with a product representation no longer computes coefficients of the element.
- Taking preimages of the identity automorphism has also been fixed. Reported and fixed by F. Hess.

## Algebraic Number Fields

- Fixes have been made to recent improvements in `MaximalOrder` computations. Reported by J. Schleucher.
- `Decomposition` of finite places of coefficient fields in extensions has been enabled. Reported by J. Schleucher.

## Arithmetic Geometry

- Some fixes have been to the package which computes invariants or twists of genus 3 curves.  Supplied by R. Lercier.
- Fixes have been made in the code for determining a bound for the difference between naive and canonical height on genus 2 Jacobians. Fix supplied by M. Stoll and S. Muller.

## Galois Groups

- Precision handling has been improved in `SplittingField` so that the valuation of the discriminant can be accurately determined. Reported by J. Schleucher.
- User provided primes using the `Prime` parameter to `GaloisGroup` are now checked to be unramified. If a user given prime is ramified, another prime will be selected for the computation. Reported by J. Schleucher.

## Lie Algebras

- A crash in `Algebra` applied to a universal enveloping algebra has been fixed.  Reported by E. Assaf.

## Local Fields

- Increased error checking of the map given as the second argument to `RelativeField` is now done. Reported by J. Schleucher.

## Permutation Groups

- Computing the quotient of permutations groups by ```quo``<G|N>``` where $N$ is the trivial subgroup has been fixed so that the result is the degree reduction of $G$ (consistent with previous behaviour).