Magma V2.16-5 Patch Notes

Algebraic Geometry¶

• The computation of affine patches of subschemes of length 1 schemes has been disallowed, consistent with the construction of subschemes of length 0 affine spaces being disallowed.
• A conflict in naming of transcendental generators in functions has been fixed. Reported by C. Quitte.

Coding Theory¶

• A leak in MinimumWeight has been fixed. Reported by M. Grassl.

Commutative Algebra¶

• A crash in Saturation for zero ideals has been fixed. Reported by N. Bruin.
• A problem with ChangeRing for boolean polynomial rings has been fixed. Repored by R. Odegard.

Finite Fields¶

• A bug in printing of non-reduced finite field elements has been fixed.

General Local Fields¶

• Some fixes to the ramified representation maps for degree 1 fields have been made.
• A fix has been made to FixedField.

Groebner Bases¶

• A crash in GroebnerBasis(S, d: Faugere := false) for a sequence of boolean polynomials has been fixed.
• A problem in the final interreduction phase for GroebnerBasis(S, d) for a sequence of inhomogeneous polynomials (leading to incorrect results) has been fixed.

Groups¶

• A runtime error when computing Subgroups of a matrix group over a ring of integers modulo m was incorrect, and has been stopped.

L-functions¶

• Some fixes and speedups for symmetric powers particularly with modular forms have been made. based on communications with J. B. Conrey.

Lists¶

• One may now obtain a sublist of a list L via L[S] where S is a sequence of indices.

Matrices¶

• Problems when computing nullspaces or images of matrices over multivariate rings and fields of fractions have been fixed. Reported by C. Quitte.
• A crash involving huge matrices over algebraic number fields has been fixed. Reported by S. Humphries.

Orders of Quaternion Algebras¶

• A bug in orders of quaternion algebras over rings other than Z has been fixed.
• Some fixes for RightIdealClasses and Conjugacyclasses over Q.

Polynomial Rings¶

• A slowness in polynomial squaring over finite fields of large characteristic has been fixed. Reported by Y. Laigle-Chapuy.
• Multivariate polynomial GCD has been sped up in the case that the degree in one variable is much larger than that in the other variables.
• Some very bad inefficiencies in multivariate polynomial powering have been fixed (and a p-adic method is now used for larger exponents). Reported by L. Finotti.
• Problems with loss of precision with polynomial multiplication over inexact rings have been fixed. Reported by A. Mellit.

Semigroups and Monoids¶

• A bug in the coercion of sequences into monoids has bee fixed, the old code would produce internal errors in case of illegal input.

Sparse Matrices¶

• A bug involing multiplication of a dense vector by a sparse matrix has been fixed. Reported by E. Thome.