I agree with your (Dave's) analysis of fuzz. APL had it, but one global
fuzz could never work for every case. Certainly adjusting the fuzz until
things work is no replacement for actually analyzing the problem.

It seems like the 1e-10 is suspect in the current proposed Interval code.
It is about as arbitrary as the 0.0001 in the Float#closeTo: code. And
maybe worse than having a global fuzz defined. That's why I like the idea
of having this "precision" as an instance variable of Interval or possibly
a method that can be overridden in some special-purpose subclass.

	mkd