Change log for Magma V2.28-17 (Released 24/1/2025)

Algebraic Number Fields

·The construction of sub<|> orders when the right hand side contains an integer or rational has been fixed. Reported by Eran Assaf.

·The deletion of quotients of orders of number fields has been fixed so that deletion of structures storing the quotients can be achieved. Reported by Eran Assaf.

·A hang in ClassGroup (coming from a call to RayClassGroup) has been fixed. Reported by Armand Brumer.

Class Field Theory

·Construction of an AbelianExtension from a number field has been improved by increasing modular arithmetic. Reported by Markus Grassl.

Commutative Algebra

·Some crashes in Groebner basis computations for ideals defined over number fields (arising from calls to TwoPowerIsogenyDescentRankBound) have been fixed. Reported by Maksym Voznyy.

·A crash when creating an "elimw" monomial order with a weights sequence given by a range has been fixed. Reported by Eric Rains.

Curves

·The hash for places of curves has been fixed so that equal places in a set can be identified. Reported by Maarten Derickx.

Groups

·A bug in the construction of a pc-group from an automorphism group of a group has been fixed. This bug could occur when the automorphism group of a p-group was in turn a p-group, and a pc-presentation of the automorphism group was constructed. Bug reported by Benjamin Sambale.

·A crash computing the kernel of a homomorphism with domain an automorphism group has been fixed. Bug reported by David Roe.

·A crash when using IdentifyGroup after using Complements has been fixed. Bug reported by David Roe.

·A crash computing th character table of a matrix group over a ring of type RngOrdRes has been fixed. Bug reported by Eamonn O'Brien.

·An error when calling MaximalSubgroups a second time on a group (where the whole group may be included in the output) has been fixed. Bug reported by Steve Humphries. type RngOrdRes has been fixed. Bug reported by Eamonn O'Brien.

Integer Ring

·A hang in the MPQS factorization algorithm for a relatively small number has been fixed. Reported by Robin Visser.

Local Rings

·The computation of relative defining polynomials has been fixed. Reported by Stefano Marseglia.

Matrices

·A bug in saturation of an integer basis matrix (arising from a call to MinimalModel) has been fixed. Reported by Maksym Voznyy.