Magma V2.12-15 Patch Notes

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 $q\gt 2^{20}$ 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.