The code for the simplifying %if is in
share/contrib/to_poly_solve_extra.lisp,
and user documentation is share/contrib/to-poly-user-doc.html.
The function %if evolved to make the to_poly_solver work the way I
wanted it to. My intention wasn't to write the ultimate simplifying
conditional. I invite everybody to examine the code for %if and make
it better. Of course, it would be great if better didn't break
to_poly_solve :)
Barton
-----maxima-bounces at math.utexas.edu wrote: -----
>To:?Richard?Hennessy?<rich.hennessy at verizon.net>
>From:?Richard?Fateman?<fateman at cs.berkeley.edu>
>Sent?by:?maxima-bounces at math.utexas.edu
>Date:?12/27/2009?05:42PM
>cc:?Maxima?List?<maxima at math.utexas.edu>
>Subject:?Re:?[Maxima]?How?to?prevent?evaluation.
>
>Richard?Hennessy?wrote:
>>
>>
>>?????It?seems?like?in?the?%if?function?both?the?then?part?and?the?else
>>?????part?are?always?expanded?even?when?only?one?needs?to?be?evaluated.
>>
>Maybe?you?could?review?what?it?is?that?%if?does,?and?see?if?it?is
>consistent?with?the?semantics?of?%if?to?evaluate?only?one?part?
>I?expect?that?it?is?not.?But?I've?forgotten?how?%if?is?supposed?to?work
>and?it?isn't?in?the?documentation?I?have.
>
>
>>???????Is?there?a?way?to?stop?evaluation?of?both?parts
>>
>
>Certainly,?but?then?it?would?be?a?different?facility.?Which?do?you
>want???Also,?Maxima?generally?is?incapable?of
>avoiding?a?calculation?because?it?might?take?too?long.?It?can,?of
>course,?stop?a?calculation??after?it?has?taken?a?while.
>But?not?usually?anticipating...
>
>_______________________________________________
>Maxima?mailing?list
>Maxima at math.utexas.edu
>http://www.math.utexas.edu/mailman/listinfo/maxima