In a Scheme program, I need to distinguish infinities and NaN values.
In Guile, it's simple, it's just the functions "inf?" and "nan?". But
when I took another implementation, I got troubles. I spent a lot of
time and tried everything -- "=", "eq?", "equal?", but nothing helped.
Fortunately, after a break, I found a simple universal solution.

If anyone cares, here is it:

http://uucode.com/blog/2007/05/30/distinguishing-usual-numbers-infini...