Magma V2.22-5 Patch Notes

Aggregates¶

• An intrinsic Components has been added for cartesian products.

Algebraic Function Fields¶

• An infinite loop in the GaloisGroup and Subfields computations for an algebraic function field defined as an extension of another algebraic function field by a polynomial with denominators has been stopped. Reported by R. Müller.

Algebraic Number Fields¶

• A sequence with universe the number field of an order will no longer be coerced (if possible) into an element of the order when given as the RHS of the ext<O| > or ideal<O| > constructors. Reported by E. Thóme.
• IsRootOfUnity was completely wrong for the case of cyclotomic fields using the sparse representation. Reported by T. Dokchitser.
• Norm(f) for a univariate polynomial f with coefficients in a field extension was wrong in general. Reported by J. Klueners.
• HilbertSymbol for number fields and prime ideals over 2 has been sped up considerably. Due to M. Kirschmer.

Coding Theory¶

• The AdditiveCode constructor that takes a linear code as input now ensures it is defined over a field.
• A problem with automorphisms of codes over Z/4Z was fixed.

Lattices¶

• The NaturalAction vararg for IsIsometric of totally definite number field lattices has had its restriction about ambient inner products removed. Noted by M. Kirschmer.
• A bug in the AutomorphismGroup function has been fixed. The bug was reported by M. Kirschmer.

Local Fields¶

• An ancient problem with Factorization over the p-adics was fixed. The problem was that a incorrect test was being used to test for squarefreeness of an auxiliary polynomial (the discriminant was used, when this could be 0 to the ambient precision without the polynomial itself having a repeated factor). This would cause occasional infinite loops. Reported by T. Dokchitser and J. Jones.

Modules¶

• Some bugs in IsIsomorphic for G-modules over the rational field have been fixed. Reported by C. Fieker.

Series Rings¶

• An improvement has been made to finding the roots of a polynomial over a series ring over a local field.

System¶

• Split no longer produces an empty first item if the string begins with a separator and IncludeEmpty is false (which is the default). Reported by T. Dokchitser.