---
title: "Magma V2.17-3 Patch Notes"
canonical: "https://docs.magma-maths.org/patchnotes/2.17-3.html"
source: "https://docs.magma-maths.org/patchnotes/2.17-3.md"
---

<a id="magma-v2-17-3-patch-notes"></a>
# Magma V2.17-3 Patch Notes

## Aggregates

- A bug that could cause crashes when iterating through multisets has been fixed.  Reported by A. Munemasa.

## Commutative Algebra

- An incorrect result in `IsFree` has been fixed. Reported by C. Quitte.

## Finitely-presented Groups

- The epimorphisms returned by the `SolubleQuotient` and `PCGroup` intrinsics have been extended to support inverse images.

## Galois Groups and Subfields

- A fix has been made to the computation of `Subfields` of number fields in relative represenation.
- A fix has been made to [`GaloisSubgroup`](../GlobalFields/GaloisGroupsAndAutomorphisms/galois.md#function-galoissubgroup-fldnum-grpperm) to use a more efficient invariant.

## Global Arithmetic Fields

- The computation of maximal orders of Kummer extensions at critical primes has been improved.

## Lie Theory

- A bug in `RestrictionMatrix` has been fixed. Reported by B. van Geemen.
- A bug in `IsSimplyConnected` and `IsAdjoint` for non-semisimple root data has been fixed.
- The function `TransversalWds` for Coxeter groups has been sped up and renamed to [`TransversalWords`](../LieTheory/CoxeterGroups/subgroups.md#function-transversalwords-grppermcox-grppermcox).
- A bug in `HighestWeightRepresentation` for Lie algebras has been fixed. Reported by A. Previtali.
- Some small issues in the computation of Chevalley bases have been resolved.
- The function [`IsChevalleyBasis`](../LieTheory/LieAlgebras/operation.md#function-ischevalleybasis-alglie-rootdtm-alglieelt-alglieelt-alglieelt) has been improved.

## Local Arithmetic Fields

- A problem with overzealous optimization in `pSelmerGroup` for p-adic fields has been fixed. Reported (and fixed) by N. Bruin.

## Matrices

- `Rows` now correctly sets the universe of the returned sequence if it is empty.  Reported by C. Quitte.
- Indexing matrices by sequences now allows the null sequence.
- `Exp` and `Log` for matrices of nilpotency resp. unipotency degree p over fields of characteristic p have been fixed. Bug reported by A. Previtali.

## Polynomial Rings

- A hang in multivariate factorization over finite fields has been fixed. Reported by T. Fisher.
- A crash in `Discriminant` for a multivariate polynomial in one variable has been fixed.  Reported by C. Quitte.

## Schemes

- Normalization of the defining equations of a map into a scheme with a non-trivial grading has been improved to remove common factors. This includes hyperellitpic curve and ambients thereof as codomains.

## Series Rings

- Finding mulitple roots of polynomials over series rings has been improved.
- Reversion of a series whose coefficient ring is not a field has been disallowed.