Magma V2.22-9 Patch Notes

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.