Magma V2.29-7 Patch Notes

Abelian Extensions¶

• HeckeCharacterGroup has been fixed when the defining ideal of the norm group differs to the conductor of the abelian extension.

• Extra printing whilst constructing an AbelianExtension from a number field has been removed. Reported by Markus Grassl.

Algebraic Number Fields¶

• SplittingField also known as NormalClosure of a number field has been made more efficient when the Abs or Opt parameters are true. Reported by Havard Damm-Johnsen.

• IdealsUpTo has been written for relative extensions.

• The computation of MultiplicationTable is now more efficient in orders which are indirect transformations of equation orders.

Algebraic Surfaces¶

• The prior CheckSing fix for MinimalModelRationalSurface has also been applied to MinimalModelRuledSurface, MinimalModelKodairaDimensionZero, and MinimalModelKodairaDimensionOne. Reported by Adam Logan.

Coding Theory¶

• An incorrect result for IsSymplecticSelfDual has been fixed. Reported by Shiroman Prakash.

Commutative Algebra¶

• The function SAT has been fixed to count exclusion clauses, thus avoiding a warning in the SAT program. Reported by Ian Smart.

• A crash in Normalisation for ideals with grevlex orderings has been fixed.

• An occasional wrong result involving very sparse matrices in the linear algebra phase of the F4 algorithm has been fixed.

• Fixed wrong results for certain Dense Groebner basis computations.

Curves¶

• UniformizingParameter has been fixed for curves with ambients having non scroll gradings. Reported by Everett Howe.

Elliptic Curves¶

• A memory management crash when checking isomorphism of elliptic curves over equal but non identical rings has been fixed. Reported by Sachi Hashimoto.

Exterior Algebras¶

• A check has been added to ExteriorAlgebra(K, n) to ensure that the base ring K is a field.

Finite Fields¶

• The procedure Embed(S, F) has been fixed so that when S and F are both defined over prime fields and have the same default polynomials then the matching generator in F is chosen for the embedding, when consistent. Reported by Sachi Hashimoto.

Language/System¶

• The case statement and intrinsic declaration now require trailing semicolons, matching all other compound statements.

• An obscure crash in signature handling has been fixed: this involved package signatures with extended types being added after other simpler signatures for the same intrinsic had already been called.

• A crash when attaching package files (involving race conditions when creating .sig files) has been fixed. Reported by Maarten Derickx.

• A crash in save/restore involving calling package intrinsics after restore has been fixed. Reported by Abhijit Mudigonda.

• A fix has been made for the problem where an error message was sometimes not printed (so there was a silent return to the top level) when printing an object with undefined attributes in a traceback. Reported by Shiva Chidambaram.

Lattices¶

• Fixed a bug in the 2-adic Jordan decomposition where the diagonal array was not recomputed after modification during the term-4 reduction step, causing incorrect results. Reported by Adam Logan.

Linear Algebra¶

• A crash in CommonEigenspaces has been fixed. Reported by Lewis Combes.

Local Fields¶

• AllExtensions has been corrected when the field is not represented as a totally ramified extension over an unramified extension. Reported by Tim Dokchitser.

• Some handling of zeros of local fields has been improved. Reported by Sachi Hashimoto.

Optimization¶

• An incorrect result in Solution(L) where L is an LP process with large integers (where the system was wrongly said to be infeasible) has been fixed. Reported by Michael Helmut Mertens.

Quaternion Algebras¶

• Fixed a bug in multiplication of an ideal in the base ring by an ideal of the quaternion algebra, leading to incorrect outputs of IsIsomorphic.