Change log for Magma V2.23-6 (Released 24/11/2017)

Abelian Fields

·The GenusField intrinsic has been corrected in some cases where the original abelian extension is not absolutely abelian. Reported by A. Bartel.

Algebras

·Constructing sets from orders of algebras has been fixed. Reported by M. Kirschmer.

·A crash in CompositionFactors for associative algebras has been fixed.

·An error in element arithmetic in Lie algebras over certain prime finite fields has been fixed. Reported by S. Garibaldi.

Analytic Jacobians

·An incorrect answer for ToAnalyticJacobian at Weierstrass points has been corrected. Reported by J. Sijsling.

Artin Representations

·A bug involving use of try/catch in Print (thus causing errors on traceback) has been fixed. Noted from a bug of J. Jones.

Conics

·A problem with reducible input was fixed. Reported by J. Voight.

Groups

·A crash in AbsolutelyIrreducibleModulesSchur has been fixed. The crash occurred when the parameters meant that the return sequence was empty. Bug reported by E. O'Brien.

Hypergeometric Motives

·A problem with a non-integral wild Euler factor was fixed. Reported by J. Jones.

Language

·It is now recommended that Print intrinsics for user-defined objects implement a "Minimal" version that in particular does not use (failing) try/catch constructions. The Magma error handler is unable to handle tracebacks when Print is overly complicated, particularly with recursive errors from try/catch then being triggered.

Local Fields

·Zeroth powers of zero are now 1 instead of an imprecise zero. Reported by J. Tuitman.

Matrices

·A failure in matrix inversion for certain types of rational matrices has been fixed. Reported by A. Page.

Number Fields

·A problem with intersection of number fields has been fixed.

·Computing an order from a sequence of elements in a number field represented as a tower of extensions has been fixed.

Polynomial Rings

·A problem with polynomial multiplication over non-commutative base rings has been fixed. Reported by Y. B. Ti.

·A crash with computing roots of polynomials over number fields has been fixed. E. GonzÃ¡lez-JimÃ©nez.

Real Numbers

·A problem with epsilonic real/imaginary parts of Roots was fixed, so that IsReal should now work as previously. Noted from a bug of J. Jones.

Real/Complex Linear Algebra

·A problem with subspaces of empty vector spaces has been fixed.