value of: None is None is None

[Lawrence D'Oliveiro]

In message <nbmdneRWl6kaibjRnZ2dnUVZ_q2dnZ2d at rcn.net>, Alan G Isaac wrote:

> Surprising for a moment, if you don't
> immediatelyrecognize it as a chained comparison.

Bugger. So much for a Python version of this 
<http://www.codecodex.com/wiki/Interval_Comparison_With_Wraparound>, then 
...