[Numpy-discussion] [Python-3000] PEP 31XX: A Type Hierarchy for Numbers (and other algebraic entities)

[Jan Grant]

On Thu, 26 Apr 2007, Dan Christensen wrote:

> Note also that double-precision reals are a subset of the rationals,
> since each double precision real is exactly representable as a
> rational number, but many rational numbers are not exactly
> representable as double precision reals.  Not sure if this means
> that reals should be a subclass of the rationals.

Not quite all: the space of doubles include a small number of things 
that aren't representable by a rational (+/- inf, for instance).




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