Magma V2.17-3 Patch Notes

Aggregates¶

• A bug that could cause crashes when iterating through multisets has been fixed. Reported by A. Munemasa.

Commutative Algebra¶

• An incorrect result in IsFree has been fixed. Reported by C. Quitte.

Finitely-presented Groups¶

• The epimorphisms returned by the SolubleQuotient and PCGroup intrinsics have been extended to support inverse images.

Galois Groups and Subfields¶

• A fix has been made to the computation of Subfields of number fields in relative represenation.
• A fix has been made to GaloisSubgroup to use a more efficient invariant.

Global Arithmetic Fields¶

• The computation of maximal orders of Kummer extensions at critical primes has been improved.

Lie Theory¶

• A bug in RestrictionMatrix has been fixed. Reported by B. van Geemen.
• A bug in IsSimplyConnected and IsAdjoint for non-semisimple root data has been fixed.
• The function TransversalWds for Coxeter groups has been sped up and renamed to TransversalWords.
• A bug in HighestWeightRepresentation for Lie algebras has been fixed. Reported by A. Previtali.
• Some small issues in the computation of Chevalley bases have been resolved.
• The function IsChevalleyBasis has been improved.

Local Arithmetic Fields¶

• A problem with overzealous optimization in pSelmerGroup for p-adic fields has been fixed. Reported (and fixed) by N. Bruin.

Matrices¶

• Rows now correctly sets the universe of the returned sequence if it is empty. Reported by C. Quitte.
• Indexing matrices by sequences now allows the null sequence.
• Exp and Log for matrices of nilpotency resp. unipotency degree p over fields of characteristic p have been fixed. Bug reported by A. Previtali.

Polynomial Rings¶

• A hang in multivariate factorization over finite fields has been fixed. Reported by T. Fisher.
• A crash in Discriminant for a multivariate polynomial in one variable has been fixed. Reported by C. Quitte.

Schemes¶

• Normalization of the defining equations of a map into a scheme with a non-trivial grading has been improved to remove common factors. This includes hyperellitpic curve and ambients thereof as codomains.

Series Rings¶

• Finding mulitple roots of polynomials over series rings has been improved.
• Reversion of a series whose coefficient ring is not a field has been disallowed.