Change log for Magma V2.18-7 (Released 28/5/2012)

Aggregates

·A memory leak associated with the creation of a record has been fixed.

Algebraic Number Fields

·Some fixes have been made to elements of non-simple number fields whose defining polynomials are non-integral or non-monic. Reported by M. Grassl.

·A crash in MaximalOrder has been fixed.

Commutative Algebra

·A hang in EliminationIdeal over Q has been fixed. Reported by A.-S. Elsenhans.

Groups

·An error in the signature of the intrinsic ClassicalIntersection has been corrected. The return value is one object of type GrpMat. There is no boolean value returned, as has been previously advertised.

·A number of memory leaks associated with cyclic permutation groups have been fixed.

·The sporadic group package has been updated by Thomas Connor and Eamonn O'Brien. This update includes new presentations on standard generators, and updated lists of maximal subgroups for sporadic groups and their automorphism groups, as described on the Atlas web site.

·The description of PrimitiveGroup(64,44) stored in the primitive group database has been corrected. Reported by Simon Guest.

·A problem with the COPlus group constructor has been fixed. Although the correct generators of the group were constructed, the group was flagged as having type COMinus, which led to various problems. Reported by Eamonn O'Brien.

Linear Codes

·Incorrect use of the automorphism group of the dual code as the automorphism group of the code (when field is not GF(2)) has been fixed. Reported by T. Feulner.

Local Fields

·A memory leak in coercion into p-adic fields over large primes has been fixed.

Rational Function Fields

·A proper error check for the base ring has been added when creating a rational function field.

Small Modular Curves

·The error messaging has been improved to give more relevant detail for some runtime errors.

System

·When SetQuitOnError(true) is in force, the exit status is now non-zero when Magma exits due to an error.