Paper 7:  Constructing the split octonions
          by Donald E. Taylor

The code for this paper takes around 10 seconds to run on a
64-bit 2.6GHz AMD processor.

Changes since book release:

V2.13:  The intrinsic SemiSimpleType has been renamed to SemisimpleType.

        A minor change has been made to adjust for the fact that
        CartanMatrix now returns a matrix over the integers, rather
        than the rationals.