--- title: "Magma V2.19-9 Patch Notes" canonical: "https://docs.magma-maths.org/patchnotes/2.19-9.html" source: "https://docs.magma-maths.org/patchnotes/2.19-9.md" --- # Magma V2.19-9 Patch Notes ## Aggregates - A crash in the reduction operator `&*` on isets has been fixed. Reported by G. Williamson. ## Algebraic Function Fields - Improvements have been made to some computations of `GaloisGroup`. - [`CoveringStructure`](../MagmaLanguage/StatementsAndExpressions/type.md#function-coveringstructure-str-str) has been refined for sets of ideals of orders of function fields. In particular, there is no covering structure for a set of ideals of a finite order and a set of ideals of an infinite order. Reported by I. Pirsic. - [`StrongApproximation`](../GlobalFields/ClassFieldTheoryForGlobalFunctionFields/related.md#function-strongapproximation-divfunelt-plcfunelt-fldfunelt) has been improved to better handle input of zero. Reported by I. Pirsic. ## Algebraic Number Fields - Memory management has been improved in one place of the class group computation. - Error checking has been improved so that `PrimitiveElement` can only be computed for ideals of maximal orders. ## Coding Theory - Determining the weight distribution of a code that is known to be MDS would sometimes work via the dual code instead. This has been fixed. ## Complex Numbers - A crash in [`RootsNonExact`](../BasicRings/RealAndComplexFields/operation-element.md#function-rootsnonexact-rngupolelt-fldre) where zero is a root of the polynomial has been fixed. Reported by P. Yatsyna. ## Elliptic Curves - A bug in the `EllipticCurve` intrinsic that produced deeply embedded rather than top-level runtime errors has been fixed. Reported by M. Zieve. ## Finitely Presented Algebras - A crash when computing the Groebner basis of some finitely presented algebras has been fixed. Reported by D. Simpson. ## Groups - Long relators in the input to [`RWSGroup`](../FinitelyPresentedGroups/GroupsDefinedByRewriteSystems/creation.md#function-grprws-rwsgroup) have been trapped before they cause memory problems by exceeding `MaxReduceLen`. Bug reported by Derek Holt. - A new intrinsic `TableOfMarks` has been installed. This may be applied to sufficiently small permutation groups and pc-groups to get Burnside’s table of marks for the group. The algorithm first computes the lattice of subgroup classes of the group. - This update contains a new implementation of the black box recognition algorithm of Beals et al for alternating and symmetric groups by Jonathan Conder. This is accessed using the intrinsic function [`RecogniseAlternatingOrSymmetric`](../FiniteGroups/AlmostSimpleGroups/group-recognition.md#function-recognisealternatingorsymmetric-grp-rngintelt), which now has different return values to the previous version. If the algorithm succeeds when given input group G, then G is isomorphic to H which is either alternating or symmetric. In this case it returns true, an isomorphism from G to H, an isomorphism from H to G, the map from G to its word group, and the map from the word group to G. The sixth value returned is true if H is the symmetric group, otherwise false. If the algorithm fails, then the first and only return value is false, the remaining 5 possible return values are unassigned. ## LSeries - A `TensorProduct` now inherits the minimal precision of its constituent parts. ## Local Rings and Fields - `Factorization` of polynomials over local rings and fields with the `Extensions` parameter set to `true` has been fixed. Reported by T. Dokchitser. ## Modules over Dedekind Domains - `IsZero` is now provided for elements of modules over Dedekind domains. Reported by M. Kirschmer. ## Orders of Associative Algebras - Memory management in the powering of elements has been fixed. ## Polytopes and Polyhedra - The new intrinsic [`VertexEdgeIncidenceMatrix`](../Geometry/Polytopes/cones-polyhedra.md#function-vertexedgeincidencematrix-torpol) can be used to recover the vertex-edge incidence matrix of a polyhedron. ## Vector Spaces - Some problems with generators in the procedural versions of `Include` have been fixed.