-----maxima-bounces at math.utexas.edu wrote: -----
>Without?thinking?about?this?too?much,?it?seems?that?there?is?a?
>possibility?of?using?a
>(relatively?strong)?interval?arithmetic?package?to?do?what?sign?is?
>supposed?to?do,
Correct me if I'm mistaken, but doing things such as x+y<2 and x-y>5
implies y<-3/2 isn't something that interval arithmetic, as generally
described, can handle. The sign code needs to be able to do things
like this. Also to be useful for sign, intervals need to be open /
closed--that might be tedious, but not terribly difficult.
One obstacle is that setting the rounding mode isn't required by
CL. For double floats, that makes it difficult to do 100%
correct interval arithmetic for all Lisp versions.
--Barton