inclusive-lower-bound, exclusive-upper-bound (was Re: Range Operation pre-PEP)

[Greg Ewing]

Gareth McCaughan wrote:
> 
> It's entertaining
> to think about what we'd have to do to ranges to
> enable the identity to be true for *all* x,y,z. :-)

I think we'd need range(y,z) where z<y to be
a sort of "anti-range" which would cancel out
part of another range when concatenated with
it. :-)

-- 
Greg Ewing, Computer Science Dept, University of Canterbury,	  
Christchurch, New Zealand
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