Change log for Magma V2.13-5 (Released 9/10/2006)

Coding Theory

·A bad leak in the function VerifyMinimumWeightLowerBound for quantum codes has been fixed. Reported by M. Grassl.

Commutative Algebra

·Some undesirable verbose information has been removed from the function HilbertSeries. Reported by E. Rains.

Elliptic Curves

·A bug in TorsionSubgroup for curves over number fields has been fixed. Previously the abstract group was correct but the points on the curve corresponding to the generators were sometimes not actually independent generators. Reported by Christian Wuthrich.

·Minor bugs in PointsQI (the routine for point searching on coverings in four descent) have been fixed.

Finite Fields

·A problem in CommonOverfield for finite fields has been fixed. Reported by H. Hubrechts.

Galois Groups

·A bug in the invariant computation resulted in errors when no invariant could be found. The problem occurred for example in the computation of the Galois group of the product of two S5 polynomials with coprime discriminant.

Invariant Theory

·The computation of primary invariants has been sped up over finite fields and the rational field by use of the Faugere F4 algorithm.

Number Fields

·A problem in Subfields(K, Degree(K)) that would always trigger an Magma Internal error has been fixed. Reported by Chris Wuthrich.

·A problem in UnitEq that caused an internal error in a case where probably no solution exists has been fixed. Reported by Costas Draziotis.

·A problem in general orders of non simple fields that would trigger internal errors on the computation of minimal polynomials has been fixed.