Lattices [HB 57]

New features:

• A new type SymGen has been created for the genus of a lattice, which builds on the previous machinery for enumeration of genus representatives by the Kneser neighbouring method. Unique local representatives provide rapid computation of equality.

Changes and new features:

• The function Genus has been changed to return a datatype for the genus of a lattice (type SymGen). The previous functionality of Genus(L) is achieved by GenusRepresenatatives(L), or by the expression Representatives(Genus(L)).
• The function SpinorGenus, introduced in Magma V2.6, has been changed in exactly the same way as Genus. The function SpinorRepresentatives(L) takes a lattice argument.