--- title: "Magma V2.22-3 Patch Notes" canonical: "https://docs.magma-maths.org/patchnotes/2.22-3.html" source: "https://docs.magma-maths.org/patchnotes/2.22-3.md" --- # Magma V2.22-3 Patch Notes ## Algebraic Function Fields - Coercion of elements in an exact constant field of a function field into the function field has been fixed for relative extensions. ## Algebraic Number Fields - The composition of automorphisms of number fields has been fixed. Reported by J. Sijsling and W. Bley. ## Algebraic Surfaces - A bug has been fixed in computing the adjoints of surfaces Reported by M.J. Martins. - A major slowdown in `FormallyResolveProjectiveHypersurface` for some kinds of inputs has been fixed. Example inputs provided by M.J. Martins. ## Arithmetic Geometry - The upper bound returned by `RankBounds` or `RankBound` for the rank of the Jacobian of a hyperelliptic curve or a cyclic cover has been refined due to a new result of Brendan Creutz. The upper bound will now always agree with parity. Example: for the curve y^2 = 5*x^6 + x^5 + x^4 - 4*x^3 - 4*x^2 + 5*x - 1, the upper bound was previously $1$ and is now $0$. ## Groups - The omission of square-free groups from the small groups database has been fixed. This created the bug of square-free groups of order > 2000 being mistaken for groups of order $3^8$. - A database of some automatic groups created from hyperbolic manifolds has been installed. Currently this contains 5389 such automatic groups. The database is contained in the file `GrpAtc.tar.gz` at the download page `http://magma.maths.usyd.edu.au/magma/download/db/ ` . ## Lattices - A problem with crashes in lattices with standard basis and inner product has been remedied. This often showed up in number field computations. - A problem with verbose printing has been fixed. - A problem with [`BKZ`](../LatticesQuadraticForms/Lattices/reduction.md#function-bkz-mtrx-rngintelt) in high dimension has been fixed. The problem was that in rare circumstances the internal kappa could change when a new short vector was found, causing a discrepancy between the approximate Gram matrix (which was reset before the kappa change) and the basis matrix. ## Matrices - Some superfluous printing in the sparse Hermite normal form algorithm has been fixed. Reported by E. Thome. - The function `Submatrix(A, I, J)` where `I` and `J` are sequences has been fixed in the case that there are zero rows or columns in the result. Reported by M. Villanueva. ## Polynomial Rings - A crash in testing whether a multivariate polynomial is square has been fixed. The algorithm to test squareness has also been sped up at the same time. Reported by A-S. Elsenhans. - The algorithm for GCD of polynomials over number fields has been sped up. - The algorithm for evaluation of a multivariate polynomial at a sequence of points in a larger ring has been sped up. ## Series Rings - The `Integral` of a series over a ring is now returned as a series over the field of fractions of the ring. - Precision handling has been improved in `Composition` of series. Reported by G. Blanco.