Change log for Magma V2.26-12 (Released 3/5/2022)

Algebraic Number Fields

·The algorithm used to compute IsSubfield for fields of degree more than 50 has been changed. Previously a root was computed by lifting but this showed to be unnecessarily expensive when for such degrees all roots can be computed in much less time. Reported by A. Pacetti.

·A crash has been fixed in MaximalOrder when the Ramification parameter is specified and the number field is defined by a non-monic or non integral polynomial. Reported by J. Rouse.

·ValuationRings and Localizations of number fields can now be constructed. Requested by A. Markowitz.

Algebraically Closed Fields

·A crash involving algebraically closed fields defined over a small finite (arising from G-module computations) has been fixed. Reported by D. Benson.

Elliptic Curves

·A crash in TatePairing(P, Q, m) where P and Q are equal has been fixed. Reported by M.R. Houben.

Local Rings

·p-adic rings constructed as a completion of the integers or rationals will now have default precision given by the Precision parameter, consistent with completions of number fields. Reported by T. Keller.

Matrix Algebra

·A crash in Centre for matrix algebras with large numbers of generators has been fixed. Reported by R. Zeier.

Representation Theory

·A crash in DirectSumDecomposition(M) for an A-module M has been fixed. Reported by D. Gvirtz-Chen.

Series Rings

·Series rings constructed as a completion of a rational function field will now have default precision given by the Precision parameter, consistent with completions of function fields. Reported by T. Keller.

System

·A crash has been fixed when printing multisets whose elements are multisets containing tuples of sets. Reported by R. van Bommel.

Valuation Rings

·ValuationRings of algebraic number fields and function fields can now be constructed.