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Article 1513 of comp.ai.philosophy:
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>From: rickert@mp.cs.niu.edu (Neil Rickert)
Newsgroups: rec.arts.books,sci.philosophy.tech,comp.ai.philosophy
Subject: Re: Daniel Dennett (was Re: Commenting on the pos
Message-ID: <1991Nov23.001207.24560@mp.cs.niu.edu>
Date: 23 Nov 91 00:12:07 GMT
References: <32905@uflorida.cis.ufl.EDU> <1991Nov21.005355.5696@husc3.harvard.edu> <centaur.690849720@cc.gatech.edu>
Organization: Northern Illinois University
Lines: 43

In article <centaur.690849720@cc.gatech.edu> centaur@terminus.gatech.edu (Anthony G. Francis) writes:
>
>I have some problems with this. First, finite state automata are not
>as powerful as (are not capable of accepting as large a class of languages
>as) push-down automata, which are not as powerful as Turing machines. 
>A Turing machine is not a FSA - it is much more powerful. Admittedly, PDA's
>and Turing machines use FSA's as part of their mechanisms, but it's a bit
>silly to call them simple table-lookup mechanisms when all of them can
>accept infinite languages.

  I'm not trying to defend zeleny - I disagree with much of what he says -
but,

  Right now I am composing this reply on a decent sized computer.  This
computer is an FSA.  I can compute the number of states, although I would
definitely need exponential notation to write it down.  The fact that it is
merely an FSA doesn't stop me compiling programs on it in various computer
languages.  Sure, I know how to generate a program sufficiently complex that
it will overflow the compiler's pushdown stack (thus proving that the machine
is not really a push down automoton).

  I could easily write a program on this machine to emulate a universal
turing machine.  But I could then prepare a program for that turing machine
on which the emulation would fail due to lack of memory.

  So your arguments about turing machines being more powerful don't have
much relevance to this discussion.

>In fact, a Turing machine can accept any language that can be specified
>in any kind of formal system. A FSA could never "capture" the standard model
>of natural numbers, but a Turing machine could. 

  Well a human could never capture the standard model of natural numbers
either.  Or at least it could not in the sense your are using in your
indictment of the FSA.  After all, if we progress at a fixed speed and have a
maximum life expectancy we too will run out of resources before we finish.

-- 
=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=
  Neil W. Rickert, Computer Science               <rickert@cs.niu.edu>
  Northern Illinois Univ.
  DeKalb, IL 60115                                   +1-815-753-6940


