Change log for Magma V2.23-10 (Released 4/5/2018)

Algebraic Geometry

·Flexes/InflectionPoints now works for affine as well as (ordinary) projective plane curves. Problem reported by C. Rito.

·A bug in Degree for non-constant maps between curves which caused errors when the domain of the map was not of Crv type has now been fixed. Reported by J. Sijsling.

·A bug in Blowup in the Rees ideal computation has been fixed. Reported by J. Sijsling.

·A bug in ambient spaces which are products of an affine and an ordinary projective space has been fixed. This was causing a number of problems including hanging computations and incorrect results for schemes lying in such ambients; in particular, those returned by Blowup of an affine scheme. Problems reported by J. Sijsling and J. Lyczak

Complex Roots

·A problem with computing complex roots of even polynomials has been fixed. Reported by S. Elsenhans.

Curves

·A fix to LPolynomial and ZetaFunction for hyperelliptic curves which don't have type CrvHyp has been made. Reported by G. McGuire.

·A check has been added to ensure that a curve has a function field before a divisor of the curve can be constructed.

Elliptic Curves

·The MordellWeilGroup machinery (including also Saturation and MordellWeilShaInformation) should now work for non-integral models (over number fields) and also over non-absolute extensions. Reported by J. Sijsling.

Graphs

·Missing functional versions of AddEdges have been added. Reported by A. Munemasa.

Group Algebras

·Incorrect testing for equality of elements of a group algera has been fixed. Reported by Matthias KÃƒÂ¼nzer.

Groups

·A crash to do with homomorphisms into an automorphism group (type GrpAuto) has been fixed.

·A crash testing conjugacy of elements of matrix groups, where the elements are not both contained in the conjugating group, has been averted by making this situation a runtime error.

·A crash when creating a set of double cosets in a finitiely presented group has been fixed. Bug reported by F. Brunault.

Hypergeometric Motives

·The EulerFactor intrinsic now immediately raises a size error when the prime powers would be too large, rather than incrementally computing until an error occurs. Reported by K. Kedlaya.

·Some problems with unbalanced hypergeometric data (used in computing guesses for wild primes) were fixed. Reported by D. Roberts.

·Minor problems with "common factors" were fixed in some intrinsics.

·The intrinsic MonodromyGroup was added.

Linear Codes

·An error in QuasiTwistedCyclicCode was corrected. This error could possibly produce incorrect results as the input polynomials were sometimes incorrectly reduced. Reported by B. Ã–zkaya and fixed by M. Grassl.

Polynomial Rings

·A problem with normal form reduction in multivariate ideals with non-field base rings has been fixed. Reported by C. Schneider.

p-Adic rings and their extensions

·An insufficient precision bug with the Factorization intrinsic was fixed. Reported by G. TornarÃ­a.

·Compatibility checking has been improved in NormGroup. Reported by J. KlÃ¼ners.

·A finite precision is now checked for in UnitGroup. Reported by J. KlÃ¼ners.