Change log for Magma V2.12-15 (Released 4/11/2005)

Class Fields of Number Fields

·IsNormal and IsAbelian would cause an infinite recursion if called with parameters All or Over and if the conductor of the extensions is not invariant under the automorphisms provided.

Codes

·A bug in testing isomorphism of two codes has been fixed. Bug reported by Gabriele Nebe.

Function Fields

·A bug involving the zero divisor and representations of divisors as a linear combination of places has been fixed.

Groups

·Incorrect generators for 3D4, 2E6, 2A returned by ChevalleyGroup when q > 220 have been fixed. Bug reported by Henrik Baarnhielm.

·The primitive groups database was badly constructed at degrees 3 and 4 and this has been fixed. In particular, the number of groups at these degrees has been corrected to 2, where 4 had been claimed but not supplied.

·RandomProcess caused an internal error when called on a group where no generators are known (e.g. matrix groups over non-standard rings).

Lattices

·A bug in testing isometry of two lattices has been fixed. Bug reported by Ivan Middleton.

Local Rings and Fields

·AutomorphismGroup now works properly on trivial extensions.

·A runtime error when powering zero elements in low-precision rings has been fixed.

·The fact that UnitGroup of infinite precision rings is not supported is now asserted with a proper error message. Furthermore a technical problem with UnitGroup (the use of a non-existing function) has been fixed.

·A problem when computing Log(1) in a variable precision ring has been fixed.

·A bug involving the computation of characteristic polynomials of local ring elements relative to their parent has been fixed.

·A problem concerning the computation of the minimal polynomial of 0 has been solved.

Number Fields

·InfinitePlaces would generate incorrect answers in relative extensions with real embeddings.

·Several memory leaks have been fixed. This affects, in particular, the computation of class groups, all computations involving real or complex conjugates of algebraic numbers and the computation of conductors.

·A bug that caused the splitting of small primes in large composite extensions to loop for ever has been fixed.

Polynomial Rings

·A bug in factorization of polynomials over function fields has been fixed. Bug reported by Kwankyu Lee.

Quaternion Algebras

·Norm now gives correct output for scalar entries.

RModules

·HasComplement would return only one value on trivial input instead of the required two.

Real Field

·IsIntegral is now working.

·Some memory leaks have been fixed. The leaks affected large parts of the number fields, the NFS and almost all real valued functions.

Schemes

·Some memory management bugs in arithmetic of divisors of curves have been fixed.