C="img64.png"
 ALT="$u_2 = v_1-
v_2$">. But as there are just as many internal  variables as elementals,
it will    not  normally  be   advantageous   to use  this    internal
representation.
Finally,  although   an element  function
may have  useful  internal
variables, the user may decide not to exploit  them.  The optimization
procedure  should still work  but at the expense of  extra storage
and computational effort.

<P>
In general, there will be a linear transformation
from the elemental variables to 