Magma V2.16-14 Patch Notes

Algebraic Curves¶

• A bug in function fields of non-plane curves has been fixed. Reported by C. Quitte.
• A bug in CurveQuotient has been fixed that was returning incorrect answers or giving an error for quotients of hyperelliptic curves when the result is of genus 1 or occasionally when the result is of genus zero.

Coding Theory¶

• EuclideanWeightEnumerator was erroneously allowed to run on codes not defined over $\mathbb{Z}_4$, and would crash as a result. This has now been fixed.

Commutative Algebra¶

• Some problems in Kernel and IsConsistent for matrices over polynomial rings and their localizations have been fixed. Reported by C. Quitte.
• The type checking in CommonEigenspaces and Diagonalization has been improved to allow number fields and cyclic fields, not just the more general algebraic fields. Reported by R. Zeier.
• A failure in Normalization when the ideal had large dimension has been fixed. Reported by O. Kedzierski.
• A problem in FreeResolution with degree 0 variables has been fixed. Reported by M. Reid.

Elliptic Curves¶

• A bug has been fixed in the simplified model computation for supersingular curves of characteristic two. Now the $a_2$ coefficient is set to zero.
• A bug has been fixed in TatePairing that was giving an error if one of the arguments was the zero point. Reported by D. Kohel.
• A crash in EtaqPairing has been fixed.

Function Fields¶

• A problem in coercion into function fields has been fixed. Reported by E. Schost.
• A bug in Subfields for a function field whose maximal order had been computed first has been fixed. Reported by N. Bruin.

Groups¶

• A bug where attributes of a GrpAuto were deleted too soon has been fixed. Bug reported by D. Howden.
• A problem with the OuterFPGroup homomorphism associated with a GrpAuto, where this map refused to compute an inverse image when the outer automorphism group is trivial, has been fixed. Bug reported by M. Kirschmer.
• A bug in the Extension function for pc-groups, where elements of the automorphism group of the first argument were not accepted as valid input, has been fixed. Bug reported by K. Andersen.
• A bug in Subgroups, where some classes of subgroups were missed when OrderEqual or OrderDividing parameters were set, has been fixed.
• A crash in permutation group code computing intersections has been fixed. Bug reported by S. Humphries.

Lattice¶

• A bug giving incorrect results in ClosestVectors for a lattice with non-standard basis and non-trivial inner product has been fixed.

Lie Theory¶

• A problem in the arithmetic with representation decompositions was fixed. Reported by R. Zeier.

Modules¶

• A crash when using KMatrixSpaceWithBasis has been fixed. Bug reported by S. Humphries.

Number Fields¶

• A bug in the code for automorphism groups of linear extensions of $\mathbb{Q}$ has been fixed.
• IsAlgebraicField now returns true for specialised number fields such as cyclic fields and quadratic fields. Reported by R. Zeier.