--- title: "Magma V2.22-7 Patch Notes" canonical: "https://docs.magma-maths.org/patchnotes/2.22-7.html" source: "https://docs.magma-maths.org/patchnotes/2.22-7.md" --- # Magma V2.22-7 Patch Notes ## Algebraic Number Fields - `Divisors` of elements of orders of algebraic number fields now gives an error when presented with an input of zero. Reported by M. Cuntz. ## Artin Representations - A precision-based bug when computing local data at bad primes was fixed. ## Binary Quadratic Forms - The `Distance` intrinsic on a single form has been removed. - `Reduction` now does not compute or return the transformation matrix if the results are being printed or only the first return value is used. - `Reduction` has been sped up. - A bug has been fixed in `IsEquivalent` that could have caused the resulting transformation matrix to not be correct. - `IsEquivalent` now allows returning transformation matrices in the real case. If non-narrow equivalence has been asked for, then the resulting transformation may produce the complementary form `<-a, b, -c>`. - `IsEquivalent` has been sped up. ## Elliptic Curves - The Cremona database of elliptic curves of small conductor has been updated to conductor 399,999. - A problem with `AnalyticRank` for elliptic curves over number fields with even degree was fixed. Reported by D. Lorenzini. - A problem with `EulerFactor` for elliptic curves over number fields with nontrivially intersecting ramification was fixed. This also appeared in `EulerFactor` for an elliptic curve twisted by an Artin representation, giving a result in a cyclotomic field rather than a complex field. Reported by D. Lorenzini. ## Galois Groups - Some improvements have been made to the computation of Galois groups. - A bug in [`SolveByRadicals`](../GlobalFields/AlgebraicFunctionFields/galois.md#function-solvebyradicals-rngupolelt) for non-monic polynomials has been fixed. Reported by P. Lisonek and fixed by Stephan Elsenhans. - The intrinsic [`GaloisSplittingField`](../GlobalFields/AlgebraicFunctionFields/galois.md#function-galoissplittingfield-rngupolelt) now applies to polynomials over number fields. This used to be the case but was removed probably by error for a time. Reported by J. Sijsling. - A bug involving Galois groups over function fields was fixed. Reported by B. Naskrecki. ## Groups - Some missing checks have been added to prevent creating matrix groups over inexact rings such as the real numbers. - An infinite loop which can arise when computing normalizers and the trivial subgroup of a pc-group has been fixed. Bug reported by T. Dokchitser. ## Hyperelliptic Curves - [`RichelotIsogenousSurfaces`](../ArithmeticGeometry/HyperellipticCurves/richelot.md#function-richelotisogenoussurfaces) has been patched, in particular for cases where the same codomain was listed 3 times rather than 3 different ones. ## Hypergeometric Motives - A problem with the computation of the conductor in the identification of the `Grossencharacter` of a Jacobi motive over Q(zeta_4) was fixed. ## L-series - A bug with the `TateTwist` of a `Grossencharacter` with nontrivial Dirichlet component has been fixed. ## Lattices - Bugs arising from computing `Coordinates` for vectors in lattices over a real field have been fixed. ## Laurent Series Rings - The `hom` constructor is now supported for Laurent series rings. ## Local Fields - A possible crash when powering by large exponents has been fixed. - A crash involving `HenselLift` was changed to give a runtime error. ## Matrix Groups - [`IrreducibleSubgroups`](../FiniteGroups/AlmostSimpleGroups/properties-lie-groups.md#function-irreduciblesubgroups-rngintelt-rngintelt) has been updated to include the insoluble irreducible subgroups of degree 3; the code was prepared by Barry Hurley. This generalises and replaces the function `IrreducibleSolubleSubgroups`. - This patch release includes a new version of the [`CompositionTree`](../FiniteGroups/MatrixGroupsOverFiniteFields/composition-tree.md#function-compositiontree-grpmat-fldfin) package which contains more efficient versions of the `ClassicalRewriting` intrinsics (Csaba Schneider) and the [`RecogniseSmallDegree`](../FiniteGroups/AlmostSimpleGroups/group-recognition.md#function-recognisesmalldegree-grpmat) intrinsic (Eamonn O’Brien). - A crash in the intrinsic `SuzukiConjugacyClasses` has been fixed by Henrik Baarnhielm. - A crash in `IsAbsolutelyIrreducible` has been fixed. ## Polynomials - The [`SmallRoots`](../BasicRings/UnivariatePolynomialRings/operation-element.md#function-smallroots-rngupolelt-rngelt-rngelt) intrinsic no longer crashes when `X` is 0. ## Real Numbers - [`ExponentialIntegral`](../BasicRings/RealAndComplexFields/special.md#function-exponentialintegral-fldreelt) now accepts negative arguments. - [`ExponentialIntegral`](../BasicRings/RealAndComplexFields/special.md#function-exponentialintegral-fldreelt), [`LogIntegral`](../BasicRings/RealAndComplexFields/special.md#function-logintegral-fldreelt), and [`DawsonIntegral`](../BasicRings/RealAndComplexFields/special.md#function-dawsonintegral-fldreelt) should be slightly more accurate in some cases. ## Rings - The functions `IsFinite` and `#` for rings now give a proper error message if an algorithm is not available (instead of sometimes returning false). Issue reported by S. Szabo. ## Schemes - A bug in `Reduction` for schemes has been fixed. Reported by S. Vishkautsan. ## Symmetric Functions - Coercion of symmetric functions into suitable polynomials rings has been made more flexible. Reported by T. Coates.