Change log for Magma V2.16-9 (Released 14/5/2010)

Coding Theory

·PunctureCode no longer allows all coordinates of the code to be removed. Reported by M. Grassl.

·A bug has been fixed in CodeComplement that could cause it to crash or return incorrect results when either argument was an additive code. Reported by M. Grassl.

Commutative Algebra

·A crash in IsRadical has been fixed. Reported by G. Brown.

·An incorrect result Saturation for ideals has been fixed. Reported by E. Rains.

Graphs

·Added convenience intrinsics NumberOfVertices and NumberOfEdges.

Language

·The extended typing feature now enables arbitrary levels of nesting for sets, indexed sets, and multisets. (Formerly only sequences would nest.)

·Calling ListSignatures with type Any properly respects the value of the Isa parameter now.

Mappings

·When mapping a sequence which is not coercible into the domain of the mapping, a sequence containing the images of the elements of the input sequence will only be returned if all those images lie in the same universe. Reported by G. Peruginelli.

Matrix Groups

·Major improvements have been made to the algorithm for proving a matrix group over a ring of characteristic zero to be finite or infinite (in particular, in the function IsFinite).

Multisets

·An error during printing of a multiset containing unsortable sequences has been fixed. Reported by S. Humphries.

·The hashing of multisets now pays attention to the multiplicities, so differing multisets with identical underlying sets will hash to different values.

Number Fields

·Testing if a fractional element lies inside an integral order was triggering runtime errors rather than simply returning false.

Polynomial Rings

·A crash in multivariate GCD over small finite fields has been fixed. Reported by M. Stoll.

Polytopes and Polyhedra

·NumberOfEdges is now typed.

SLP Groups

·A slowdown when large numbers of straight line programs were created has been addressed. Reported by E. O'Brien.