Change log for Magma V2.27-7 (Released 23/12/2022)

Algebraic Geometry

·A bug in Extend when alternate equations become undefined has been fixed. Reported by T. Keller.

·Bugs in Genus4GonalMap and Genus5GonalMap have been fixed. Reported by D. Roe.

Algebraic Number Fields

·The handling of empty sequences on the RHS of the ideal<|> constructor has been improved. Reported by M. Kirschmer.

Arithmetic Geometry

·A bug in HeightConstant for Jacobians of hyperelliptic curves. Fix provided by M. Stoll.

·A hang in Chabauty has been fixed. Reported by N. Bruin and fix provided by M. Stoll.

·A crash in HyperellipticCurveFromIgusaClebsch for certain types of input has been fixed. Reported by E. Costa.

Complex Field

·A crash in complex root finding (arising from ReducedMinimalWeierstrassModel) has been fixed. Reported by E. Costa.

Elliptic Curves

·A crash in IsogenousCurves for certain types of input has been fixed. Reported by M. Voznyy.

Galois Groups

·A crash in the computation of Subfields and GaloisGroup of a relative extension of function fields has been fixed. Reported by D. Karagueuzian.

Group Theory

·A crash in CharacterTable applied to soluble groups with very large number of classes has been fixed. Reported by D. Roe.

Lattices

·An error in GenusRepresentatives has been fixed. Reported by R. Scharlau.

Local Rings

·Enumerating the elements of an extension of a p-adic ring with precision 1 has been fixed to ensure there are no duplicates in the enumeration. Reported by C. Putz.

Matrix Algebras

·A case in the function in PrimitiveIdempotents where the result did not contain normal matrices has been fixed. Reported by J. Maglione.