expand in ev



Currently, ev(...,expand) is equivalent to
ev(...,expop:maxposex,expon:maxnegex).

This means that expansion is active throughout the evaluation of ..., which
sometimes gives surprising results:

     ex:(x+1)^2*(x-1)^2;
     part(ex,1),expand => x^4
         equivalent to part(ex,1),expop:maxposex,expon:maxnegex
         equivalent in effect to part(expand(ex),1)
cf.
     part(ex,1),ratsimp => x^2-2*x+1
         equivalent to ratsimp(part(ex,1))

I think it would be more consistent and thus easier to understand if expand
worked like every other command in ev, namely that it called the command
*after* evaluating the expression.

EV would remain weird and confusing in other ways, but at least this would
be simpler....

            -s