Change log for Magma V2.22-9 (Released 11/4/2017)

Aggregates

·IsEmpty now also works on tuples.

Algebraic Fields

·An ideal of an order of an algebraic number or function field can be contructed from an element of the bottom coefficient ring (Z, a polynomial ring or a valuation ring) using !!. Reported by C. Quitte. This fixes a bug in RingClassGroup when the input is an order of a quadratic field (RngQuad).

Analytic Jacobians

·A bug reported by J.-S. Mueller was fixed.

Class Field Theory

·A bug in HeckeCharacterGroup of an abelian number field was fixed. Reported by P. Stucky.

Coding Theory

·The function Transversal(C, V), where C is a linear code and V is its ambient space, has been added.

Dirichlet characters

·Non-primitive characters over Q now include their modulus when printed.

Elliptic Curves

·A problem with GaloisRepresentation was fixed. Reported by N. Freitas.

·Magma-level printing of elliptic curves over the rationals no longer prints the universe of the coefficient sequence.

Extended Reals

·It is now allowed to use div to divide an infinity by an integer.

Finite Fields

·Fixed a bug in Log that could cause a crash in rare circumstances.

·New procedure SetZechLimit(n) is added, which allows one to set the limit L so that the Zech representation will be used for any non-prime finite field with size at most L (default is 2^20 and max is 2^30). The corresponding function GetZechLimit() returns the current limit.

Groebner Bases

·A bug in the FGLM parameter handling for the function GroebnerBasis has been fixed. Reported by M. Kudo.

Groups

·A bug when constructing the centralizer of an element in a general linear group has been fixed. Bug reported by E. O'Brien and H. Dietrich.

·An incorrect type FinFld in signatures for BorelSp and ExtendedWeylGroup has been fixed. (It is now the correct FldFin.) Reported by G. Williamson.

·A crash to do with finitely presented groups has been fixed. Bug reported by I. M. Isaacs.

Hyperelliptic Curves

·A bug in ShiodaInvariants has been fixed. Problem noted and solution supplied by J. Sijsling.

I/O

·The intrinsics WriteCheck and WriteBytesCheck have been added.

Language

·A break or continue statement is now allowed from within a try-catch statement.

·A problem with clear where identifiers had wrong values has been fixed. Problem reported by C. Meaney.

Lattices

·A bug with internal precision in BKZ was remedied.

Newton Polygons

·A bug in the construction of a newton polygon of a polynomial with a zero coefficient over an infinite precision p-adic field has been fixed.

Polynomial Rings

·The previously omitted function SquarefreeFactorisation has been added as a synonym for SquarefreeFactorization. Reported by C. Meaney.

·A crash in multivariate resultant over the integers has been fixed. Reported by J. Doyle.

Series Rings

·Memory handling when taking a fractional power of a series not over the rationals has been fixed. Reported by G. Blanco.

System

·A slowdown in the memory manager when there were many free blocks of similar size has been fixed. Problem reported by M. Grassl.

p-adic Rings

·A bug with coercion sometimes failing for elements between two p-adic quotient rings with the same (large) p was fixed. Reported by J.-S. Mueller.

·It is now possible to apply HenselLift to a polynomial and a sequence of 1 polynomial, not just more than 1. Reported by C. Doris.