Change log for Magma V2.21-12 (Released 26/4/2016)

Algebraic Function Fields

·Error checking for non simple fields in intrinsics using Cartier representation has been improved.

·Printing of elements of non-simple fields has been fixed in some cases. Problem reported by M. Grassl.

Elliptic Curves

·A glitch (runtime error in some examples) in elliptic curve Chabauty has been fixed. Reported by B. Naskrecki.

Group Algebras

·A bug in scalar multiplication in group algebras in the presence of zero divisors has been fixed. Reported by U. Thiel.

Hyperelliptic Curves

·The functions Points and jPoints for point search on Jacobians of hyperelliptic curves now have an optional parameter ReturnAll. When true, the functions return all points found in the search, including any larger than the height bound.

·Minor problems (causing runtime errors in a couple of examples) have been fixed in TwoCoverDescent. Reported by A. Sutherland.

·A bug in Degree3Subcovers has been fixed.

Noncommutative Groebner Bases

·A bug involving the final interreduction of a noncommutative Groebner basis when a degree bound is present has been fixed. Reported by J. Blasiak.

Number Fields

·The sieve algorithm used inside ClassGroup is now always switched off for fields of degree 6 (and higher), in order to avoid crashes. (One example was reported by A. Joux and A. Gelin.)

·PicardGroup now accepts fields of type FldQuad.

Polynomials

·A bug causing an incorrect result when powering extremely high degree binary polynomials in quotient rings has been fixed. Reported by R.P. Brent.

System

·A potential crash in the profiler has been fixed; it could arise when the return type of an intrinsic was invalid. Reported by W. B. Ladd.