Thomas A. Russ <tar@sevak.isi.edu> wrote:
+---------------
| rpw3@rpw3.org (Rob Warnock) writes:
| >   (defun resistor-ohm-law (&key v r i)
| >     (cond
| >       ((and v i r)
| >        (error "May not specify all three parameters!"))
| 
| Actually, at this point, I would evaluate Ohm's law and only signal
| an error if it wasn't valid.
+---------------

An iteresting idea, except that it violates one of the prime tenets
of dealing with floating-pont numbers, which is *never* to compare
them for exact equality!!  [And if you're not going to use "=", then
you would need an additional :EPSILON keyword to specify the acceptable
error in the comparison, and that's just getting ugly...]


-Rob

-----
Rob Warnock			<rpw3@rpw3.org>
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