Change log for Magma V2.21-7 (Released 9/10/2015)

Algebraic Number Fields

·The input accepted by GaloisSplittingField has been made clearer.

·A bug in the computation of a UnitGroup of an order of a number field has been fixed.

Commutative Algebra

·A crash involving computing free resolutions over number fields has been fixed.

·An inefficiency in some computations of Groebner bases over finite fields of characteristic 2 has been fixed.

·A missing error check for GrÃ¶bner basis input polynomials with too high degree when a degree limit is present has been fixed. Reported by P.-J. Spaenlehauer.

Dedekind Modules

·The reduction of elements in quotients of Dedekind modules has been fixed.

FP Algebras

·A hanging problem with embedding scalars into FP algebras has been fixed. Reported by S. Schoennenbeck.

Hypergeometric Motives

·The ComplexEvaluation intrinsic for Jacobi motives was fixed to properly include the Tate-twsting factor.

·A bug with insufficient precision with Grossencharacter of a Jacobi motive has been fixed. Reported by D. Roberts.

·Problems with identifying the correct infinity-type for the Grossencharacter of a Jacobi motive have been remedied.

L-Series

·A bug with the EulerFactor of a Hilbert modular form at a prime which splits into different degree ideals was fixed (the relevant sequence could not hold both polynomials and power series). Reported by J. Voight.

Local Fields

·The check on the leading coefficient in IsEisenstein has been fixed. Reported by R. Mueller.

Matrices

·A crash on the 32-bit version in LLL for matrices over univariate polynomial rings has been fixed.

Primality Testing

·A bug with IsPrime for numbers of the form N^2+1 has been fixed.

Quaternion Algebras

·A problem with IsQuaternionAlgebra and orders has been fixed, with some confusion between trace and norm and the their reduced versions. Reported by J. Voight and J. Sijsling.

Schemes

·Error checking in InverseDefiningPolynomials for a map between schemes which is a composition of maps between schemes has been improved.