Magma V2.25-6 Patch Notes

Finite Fields¶

• The default strategy for selecting the Pohlig-Hellman discrete logarithm algorithm has been improved for finite fields. Also, if $K$ is a finite field, one may now set the attribute K```UsePHLog (with the backquote operator) to whether the Pohlig-Hellman will be used when computing logarithms in $K$. Issue reported by J. Jean.

Galois Theory¶

• A recently introduced bug in the intrinsic SolveByRadicals for polynomials over the rational field has been fixed.

Groebner Bases¶

• A crash when computing large Groebner bases over non-prime finite fields of characteristic 2 has been fixed. The F4 algorithm for such inputs in the sparse case has been improved also. Reported by D. Craven.
• Incorrect sign handling when computing coordinates of polynomial/vectors in ideals/modules defined over exterior algebras has been fixed. Reported by M. Barakat.
• A missing error check for noncommutative Groebner basis computation over unsupported rings has been added. Reported by R. Bruner.

Group Theory¶

• Operations involving sets of permutation groups no longer compute a minimal set of generators, which should make them faster in almost all cases.
• A crash in p-group generation (for example, intrinsics GeneratepGroups and Descendants), caused by a subtle limit in the Magma memory manager has been fixed. Reported by M. Newman.

Lattices¶

• Setting one of the attribues Minimum, Kissing Number, or Theta Series when one of the other attributes is set will no longer print the theta series.

Local Fields¶

• A bug in the construction of a local field which is not a scalar multiple of a monic integral polynomial has been fixed. Reported by S. Marseglia.

Matrices¶

• A bug when computing the determinant of matrices over polynomial rings over non-domains has been fixed. Reported by J. Voight.

Number Fields¶

• Computing primes in the discriminant of an order whilst computing a MaximalOrder has been improved by using the Smith form of the trace matrix.
• A bug has been fixed in the computation of maximal orders using the Discriminant and Ramification parameters. Reported by J. Klüners.
• A bug in coercion of elements in large towers has been fixed. Reported by M. Grassl.
• In the construction an AbelianExtension of a number field, additional checking has been added to ensure that extensions arising are both normal and abelian. Reported by M. Grassl.

Polynomial Rings¶

• A bug in Normalize for univariate polynomials defined over integer residue class rings has been fixed, so the result is guaranteed to be unique. Reported by L. Notarfrancesco.
• The check for overflow in the number of monomials in a multivariate polynomial ring was not quite correct and has been fixed. Reported by T. Verron.

Quaternion Algebras¶

• A bug when computing of the discriminant of a quaternion algebra has been fixed by J. Voight. Reported by M. Schein.

Schemes¶

• A crash in IsInvertible applied to a map between schemes when the parameter Maximal is set to true has been fixed. Reported by N. Bruin.

System¶

• Power structures may now be compared and placed in sets.

Toric Varieties¶

• Maps involving Toric Varieties have been improved. Reported by A. Laface.