Change log for Magma V2.14-9 (Released 16/1/2008)

Aggregates

·A crash in associative arrays (when keys are removed) has been fixed. Reported by B. Kerby.

Elliptic Curves

·A bug in EllipticCurve applied to genus 1 hyperelliptic curves has been fixed. Reported by Hendrik Hubrechts.

Incidence Structures

·Constructors for the various incidence structures have been extended to accept sets of vectors and sparse matrices to specify the blocks. In particular, the orbit of a vector under the action of a group may be used to specify the blocks.

·A new intrinsic function Design(I, t, l) has been added to convert incidence structure I to a t-(v,k,l) design. This is very quick as no checks are performed that I really is such a design. That responsibility lies with the user. The new function is intended for use when the call IsDesign(I,t) has returned true, l.

Matrix Groups

·A hang in proving a matrix group finite over a cyclotomic field has been fixed. Reported by M. Grassl.

·The methods used to find the order of a matrix over a number field, rationals or integers, including determining whether they have finite or infinite order, have been improved. Follows query from H. Baarnhielm on time taken by the order algorithm.

Modules

·The functions AHom and GHom may now be applied to modules over the rational field. Restriction reported by P. Brooksbank.

Polynomial Rings

·A crash in polynomial arithmetic over residue class rings has been fixed. Reported by L. Finotti.

Real Numbers

·Fixed RealToIntegerExponent to return odd values only, as claimed. Reported by M. Grassl.