---
title: "Magma V2.14-12 Patch Notes"
canonical: "https://docs.magma-maths.org/patchnotes/2.14-12.html"
source: "https://docs.magma-maths.org/patchnotes/2.14-12.md"
---

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# Magma V2.14-12 Patch Notes

## Algebraic Curves

- Some bugs have been fixed in the `Divisor` intrinsics giving the divisor corresponding to a zero-dimensional subscheme of a curve.

## Algebraic Function Fields

- The completion mapping for the field defined by $y = 0$ has been fixed.
- `DecompositionType` for places of the rational function field has been fixed.

## Coding Theory

- `AutomorphismGroup` for additive codes now returns a more helpful error message when the code is not defined over $GF(4)$. Reported by M. Grassl.

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## Documentation - Handbook

- A new, corrected version of the Handbook has been compiled.

## Elliptic Curves

- A crash in point division has been fixed. Reported by R. Conceicao.
- A bug in the computation of twists of supersingular elliptic curves in characteristics 2 and 3 has been fixed. Reported by J. Cremona.

## Galois Groups

- The computation of Galois groups of polynomials over $\mathbb{Q}(t)$ (rational function field over the field of rational numbers) has been completely rewritten. As a result, a number of outstanding bugs with wrong results have been fixed, but there is a significant slowdown on some examples. Bugs reported by Kurt Foster and Martin Hintermeier.
- A few minor problems when using invariants over complicated rings has been fixed. Without the fix, certain computations over $\mathbb{Q}(t)$ could cause internal errors.
- A bug in the computation of the number of multipliactions in an invariant has been fixed. Without the fix, the function could enter an infinite recursion and terminate Magma.
- A bug in the computation of a bound for the values of the “ProdSum” invariant has been fixed. In certain examples, the wrong bound (too small in general) could have caused wrong results.

## Groups

- A bug in finitely presented groups has been fixed. Bug reported by Jack Button.
- A bug in `Subgroups` function, when restricted to elementary abelian subgroups, has been fixed. Bug reported by Markus Grassl.
- A bug when constructing a sequence of rewrite system groups has been fixed. Bug reported by Jack Schmidt.
- A bug when evaluating an empty sequence of words using `Evaluate` has been fixed. Bug reported by Henrik Baarnhielm.
- The function `CompositionSeries` for a permutation group has been upgraded and corrected to give a full composition series for the group, rather than stopping at the soluble residual.

## Hyperelliptic Curves

- A bug in the creation of places on hyperelliptic curves has been fixed.

## Matrices

- A slow down in matrix multiplication over the rationals has been fixed. Reported by B. Ricard.

## Number Fields

- A bug in the computation of conjugates of orders in relative extensions has been fixed. The old code would cause a runtime error.

## Orders of Associative Algebras

- Creation of ideals by multiplication of an order and an element has been fixed.
- Equality of orders has been fixed.
- Some bugs in some operations with orders and their elements have been removed.

## Real Fields

- [`BesselFunction`](../BasicRings/RealAndComplexFields/gamma-bessel.md#function-besselfunction-rngintelt-fldreelt) has been fixed.