Change log for Magma V2.23-9 (Released 16/3/2018)

Class Field Theory

·A crash in class field computations arising from the construction of irreducible modules has been fixed. Reported by P. Lisonek.

Genus 2 Curves and their Jacobians

·A problem with heights (derived from Kummer surface computations) for torsion points on the Jacobians was fixed. Also, the height is now returned as zero to the user (rather than default) precision. Reported by R. van Bommel.

Groups

·A crash when finding a Centralizer in a unipotent matrix group has been fixed. Bug reported by Dave Benson.

·A crash when computing quotients of FP groups has been fixed.

Lattices

·A crash with insufficient precision in large dimensional real lattices has been changed to give an error message.

Module Theory

·A crash in Constituents for general R-modules defined over characteristic zero fields has been fixed.

Polynomial Rings

·An incorrect result for polynomial factorization over finite fields has been fixed. Reported by J. Bauch.

System

·Modifying null sequences in record fields (or object attributes) now works somewhat better. Reported by C. Doris.

p-adic Extensions

·The NumberOfExtensions intrinsic did not correctly adjust for non-absolute input. Reported by C. Doris. An initial fix has been made, though the code is being perused for further non-uses of Absolute-constructs.

·The Eltseq of infinite valuation zeros has been fixed. Reported by C. Doris.