Many of the functions in abs_integrate, for example, return false when the
function is unable to determine an antiderivative. Oh sure, silly things
such as integrate(1,x,0,false) break this scheme. Fixing this in some
sturdy way isn't worthwhile, I think. If you want a function to indicate
failure by returning %void instead of false or a nounform, that's fine.
You could even tell Maxima that assignments to %void aren't allowed.
Barton
-----maxima-bounces at math.utexas.edu wrote: -----
>To:?"Stavros?Macrakis"?<macrakis at alum.mit.edu>
>From:?"Richard?Hennessy"?<rich.hennessy at verizon.net>
>Sent?by:?maxima-bounces at math.utexas.edu
>Date:?10/04/2009?09:06PM
>cc:?Maxima?List?<maxima at math.utexas.edu>
>Subject:?Re:?[Maxima]?Void?in?Maxima
>
>
>
>
>
>
>
>What?about?the?possibility?of?creating?a?new?system
>variable?called?void?or?%void?that?would?have?the?properties?that?I
>described.??I?think?this?is?desirable?because?many?times?I?think?a
>function
>should?not?return?a?value?when?the?function?fails?at?its?job.??This
>might?be?a?way?to?resolve?how?to?handle?all?of?the?problems?with?'und,
>'ind,
>'inf?and?'minf.
>
>Rich
>
>
>??-----?Original?Message?-----
>??From:
>??Stavros
>??Macrakis
>??To:?Richard?Hennessy
>??Cc:?Maxima?List
>??Sent:?Sunday,?October?04,?2009?11:00
>??AM
>??Subject:?Re:?[Maxima]?Void?in
>Maxima
>
>
>??On?Sun,?Oct?4,?2009?at?9:09?AM,?Richard?Hennessy
><rich.hennessy at verizon.net>
>??wrote:
>
>??Is?there?a?way?to?cause?a?function?to?have?no?return
>????value.
>
>No.
>
>It?is?possible?to?create?a?symbol
>??of?length?0?using??intern("$")?which?has?a?zero-length?printed?form,?but
>this
>??has?none?of?the?properties?you
>??want.
>
>?????????-s
>
>
>
>
>
>??_______________________________________________
>Maxima?mailing
>??list
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