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From: Ian Kelly <ian.g.kelly@gmail.com>
Date: Tue, 19 Aug 2014 16:21:41 -0600
Subject: Re: 'is not' or '!='
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On Tue, Aug 19, 2014 at 3:00 PM, Marko Rauhamaa <marko@pacujo.net> wrote:
> For a more worthy attempt, we'll have to take a look at Scheme (<URL:
> http://www.scheme.com/tspl2d/objects.html>):

Those are invariants, not a definition.  The actual definition is
found in the paragraph above:

"In most Scheme systems, two objects are considered identical if they
are represented internally by the same pointer value and distinct (not
identical) if they are represented internally by different pointer
values, although other criteria, such as time-stamping, are possible."

In other words, object identity in Scheme is also established by an
integer that may or may not correspond to a memory address. How is
this any different from Python's definition?