add integration of maxima's non-zero detection, see how good it is

[GoogleCodeExporter]

In order to do scalable evolution of numerical functions we need a
heuristic procedure for determining if a particular subexpression is
nonzero over a particular range of inputs (e.g. for an expressions of n
variables, and n-dimensional cube). There are a bunch of ways to do this,
interval arithmetic being the simplest, affine arithmetic being better
(http://en.wikipedia.org/wiki/Affine_arithmetic), etc. Maxima also has a
built-in function for this. How good is it? What method does it use? I
don't know...

Original issue reported on code.google.com by [email protected] on 8 Dec 2008 at 5:22