Change log for Magma V2.11-12 (Released 11/1/2005)

Algebraic Geometry

·Several bugs in the linear systems machinery have been fixed including those in the AdjointLinearSystem call.

·The ArithmeticGenus intrinsic has been extended to work with schemes defined in product or weighted projective ambient spaces.

Commutative Algebra

·A bug which caused a crash when factoring polynomials over algebraic function fields has been fixed.

·Coercion from rational function field elements back to the base field has been fixed to work more generally.

·Extension has been fixed to handle the empty sequence.

Fields

·Several bugs in relating to using Roots with polynomials over the p-adics with zero roots have been fixed.

·A bug in the coercion of elements from p-adic fields to the residue class field has been fixed.

·Problems with large towers of number fields mixing simple and non-simple extensions have been fixed. The problems were most likely to cause internal errors in polynomial factorisation.

Groups

·A bug which caused a crash when constructing a projective unitary group over a field of size greater than 220 has been fixed.

·A bug with FPGroupStrong for matrix groups, where the presentation found did not necessarily contain a presentation for each basic stabilizer (and so wasn't a strong presentation) has been fixed.

·A bug when constructing generic abelian groups over an aggregate of integers has been fixed.