Re: Cycle detection problems: #442, #338, "equal?" John Cowan (31 Aug 2012 15:22 UTC)
Re: Cycle detection problems: #442, #338, "equal?" John Cowan (31 Aug 2012 21:47 UTC)
Re: [Scheme-reports] Cycle detection problems: #442, #338, "equal?" Vassil Nikolov (01 Sep 2012 03:22 UTC)

Re: [Scheme-reports] Cycle detection problems: #442, #338, "equal?" Vassil Nikolov 01 Sep 2012 03:22 UTC

On Fri, 31 Aug 2012 11:21:18 -0400, John Cowan <cowan@mercury.ccil.org> said:

> John Boyle scripsit:
> ...
>> Actually, come to think of it, there is one fact about equal? that is true
>> for all non-cyclic structures that isn't true under unfolding: if (equal? a
>> b), then not (equal? (cons <something> a) b).

> That's just a way of encoding the paradoxical fact that one plus infinity
> is still equal to infinity.

  Though "equal" in the previous sentence does not refer to the
  (usual) equality relation between numbers (but to a different
  relation).  Infinity is a funny thing...

  ---Vassil.

--
Vassil Nikolov | Васил Николов | <vnikolov@pobox.com>

"Be careful how you fix what you don't understand."  (Brooks 2010, 185)

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