This package also includes new versions for the vector and matrix
classes VEC and MAT.  You need them only for 'Xdemo/3d.sa'.  They
should be compatible to the old version, but provide new functions
'gauss', 'det', and 'inv' for matrices.

Copy the files 'vec.sa' and 'mat.sa' into your Sather library
directory (but keep the original files as a backup!).
