Magma V2.21-3 Patch Notes

Commutative Algebra¶

• An bug in IsPrime for positive-dimensional ideals over finite fields of medium characteristic has been fixed. Reported by N. Bruin.

Dirichlet and Hecke Characters¶

• The creation intrinsics DirichletCharacter and HeckeCharacter can now take a list as an argument instead of a tuple.
• The intrinsic GrossenTwist has been expanded to include twists by Hecke characters of the same modulus, and also returns a kernel corresponding to characters that are trivial on the given data.

Elliptic Curves¶

• A crash with large degrees in FrobeniusMap is now avoided.
• A problem with computing Euler factors at good primes (over a number field) which divide the denominator of the a-invariants has been fixed. Reported by F. Brunault.

Groups¶

• A crash in IsCyclic when applied to the trivial matrix group has been fixed. Bug reported by Andrew Sutherland.
• A crash to do with HomomorphismsProcess, when no homomorphisms are found, has been fixed. Bug reported by Jan Karabas.

Number Fields¶

• The meet of 2 number fields which are defined as extensions of different coefficient fields has been fixed.

Polynomials¶

• A problem with multiplication of polynomials whose trailing terms were inexact elements of an exact ring, for instance a constant coefficient O(t^4) in a power series ring of fixed precision 20 over GF(3), has been fixed. Reported by B. Allombert in the context of factorization of polynomials over Laurent series rings.
• A crash when taking GCD of polynomials over a GaloisRing has now been disallowed.
• A crash in factorization of multivariate polynomials over a number field with a non-monic defining polynomial has been fixed.

Sparse Matrices¶

• A missing error check in Echelonize has been inserted. Reported by R. Zeier.

Symmetric Function Algebras¶

• Taking the characteristic of a symmetric function algebra no longer crashes.
• Polynomial arithmetic over symmetric function algebras no longer crashes. Reported by A. Duncan.

System¶

• The description of GetDefaultRealField now has the correct return type.
• The deprecated FldPr and FldPrElt types have been removed. Note: As a consequence, workspaces saved before this patch release will not be able to be properly restored by it.