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From: aweinste@Diamond.BBN.COM (Anders Weinstein)
Newsgroups: comp.ai,comp.cog-eng
Subject: Re: The symbol grounding problem (Reply to Ken Laws on ailist)
Message-ID: <6642@diamond.BBN.COM>
Date: Wed, 17-Jun-87 14:32:20 EDT
Article-I.D.: diamond.6642
Posted: Wed Jun 17 14:32:20 1987
Date-Received: Sun, 21-Jun-87 10:16:10 EDT
References: <764@mind.UUCP> <768@mind.UUCP> <770@mind.UUCP> <6174@diamond.BBN.COM> <847@mind.UUCP> <849@mind.UUCP>
Reply-To: aweinste@Diamond.BBN.COM (Anders Weinstein)
Organization: BBN Laboratories, Inc., Cambridge, MA
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In article <849@mind.UUCP> harnad@mind.UUCP (Stevan Harnad) writes:
>                                   As long as the requisite
>information-preserving mapping or "relational function" is in the head
>of the human interpreter, you do not have an invertible (hence analog)
>transformation. But as soon as the inverse function is wired in
>physically, producing a dedicated invertible transformation, you do
>have invertibility, ...

This seems to relate to a distinction between "physical invertibility" and
plain old invertibility, another of your points which I haven't understood.

I don't see any difference between "physical" and "merely theoretical"
invertibility.  If a particular physical transformation of a signal is
invertible in theory, then I'd imagine we could always build a device to
perform the actual inversion if we wanted to. Such a device would of course
be a physical device; hence the invertibility would seem to count as
"physical," at least in the sense of "physically possible".

Surely you don't mean that a transformation-inversion capability must
actually be present in the device for it to count as "analog" in your sense.
(Else brains, for example, wouldn't count). So what difference are you trying
to capture with this distinction?

Anders Weinstein
BBN Labs