<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:arial, helvetica, sans-serif;font-size:12pt"><P>Hi Katrin,</P>
<P>you exactly understood my intent. I have already shown to my students several turing machine simulators. Now I would like to shown them the equivalence with grammars. And I would like to have them actually see how a grammar can do the same computation performed by a (tape-limitated) turing machine.</P>
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<DIV>Stefano<BR> </DIV>Stefano Federici<BR>-------------------------------------------------<BR>Università degli Studi di Cagliari<BR>Facoltà di Scienze della Formazione<BR>Dipartimento di Scienze Pedagogiche e Filosofiche<BR>Via Is Mirrionis 1, 09123 Cagliari, Italia<BR>-------------------------------------------------<BR>Tel: +39 349 818 1955 Fax: +39 070 937 1870
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<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: times new roman, new york, times, serif">----- Messaggio originale -----<BR>Da: Katrin Erk <katrin.erk@mail.utexas.edu><BR>A: stefano federici <s_federici@yahoo.com><BR>Cc: corpora@uib.no<BR>Inviato: Giovedì 10 aprile 2008, 15:33:59<BR>Oggetto: Re: [Corpora-List] Sorry, my mistake, I need a Context-DEPENDENT grammar simulator<BR><BR>Hi Stefano,<BR><BR>if all you need is a simulator for context-sensitive grammars, that<BR>should be simple: context-sensitive languages are accepted by linearly<BR>bounded automata, which are just Turing machines plus the guarantee<BR>that you can do with a linearly bounded amount of tape. If you google<BR>"turing machine simulator", you'll find several of them.<BR><BR>Hope that helps,<BR>Katrin<BR><BR>On Thu, Apr 10, 2008 at 8:20 AM, stefano federici <<A href="mailto:s_federici@yahoo.com" ymailto="mailto:s_federici@yahoo.com">s_federici@yahoo.com</A>>
wrote:<BR>><BR>><BR>><BR>> I guess that I stated my correct request in the wrong way. I just need a<BR>> general simulator for context-dependent grammars that I can use to show to<BR>> my students (by creating a toy grammar) how a language analyzer for a<BR>> context-dependent grammar does works. I don't need any real<BR>> context-dependent grammar for whatever language.<BR>><BR>><BR>><BR>> I hope that this will give me some positive answer.<BR>><BR>><BR>><BR>> Thanks for your time<BR>><BR>><BR>> Stefano<BR>><BR>> Stefano Federici<BR>> -------------------------------------------------<BR>> Università degli Studi di Cagliari<BR>> Facoltà di Scienze della Formazione<BR>> Dipartimento di Scienze Pedagogiche e Filosofiche<BR>> Via Is Mirrionis 1, 09123 Cagliari, Italia<BR>> -------------------------------------------------<BR>> Tel: +39 349 818 1955 Fax: +39 070 937
1870<BR>><BR>><BR>><BR>> ----- Messaggio originale -----<BR>> Da: John F. Sowa <<A href="mailto:sowa@bestweb.net" ymailto="mailto:sowa@bestweb.net">sowa@bestweb.net</A>><BR>><BR>> A: stefano federici <<A href="mailto:s_federici@yahoo.com" ymailto="mailto:s_federici@yahoo.com">s_federici@yahoo.com</A>><BR>> Cc: <A href="mailto:corpora@uib.no" ymailto="mailto:corpora@uib.no">corpora@uib.no</A><BR>> Inviato: Giovedì 10 aprile 2008, 13:14:23<BR>> Oggetto: Re: [Corpora-List] Sorry, my mistake, I need a Context-DEPENDENT<BR>> grammar simulator<BR>><BR>><BR>><BR>> Stefano,<BR>><BR>> You are asking for somebody to hand you the Holy Grail:<BR>><BR>> > What I need is a context-DEPENDENT grammar simulator.<BR>><BR>> Chomsky's original definition of context sensitive grammar<BR>> rules was very general, but not very practical for dealing<BR>> with the kinds of context dependencies
in natural languages<BR>> (or even the much, much simpler programming languages).<BR>><BR>> The number of different kinds of context dependencies in NLs<BR>> is enormous, and many different branches of linguistics (both<BR>> theoretical and computational) have evolved to deal with<BR>> various aspects in an open-ended variety of complex ways.<BR>><BR>> At one extreme, any background knowledge that people have in<BR>> their heads (or computers have in their knowledge bases) may<BR>> be necessary for disambiguating a sentence in context.<BR>><BR>> At the other extreme, a table of names, references, symbols, etc.,<BR>> is a highly efficient mechanism for keeping track of anaphoric<BR>> references in NLs and symbol declarations in programming languages.<BR>><BR>> A complete list of all the kinds of context dependencies and how to<BR>> describe, formalize, and implement them would touch on
essentially<BR>> every aspect of linguistics, logic, and knowledge representation.<BR>><BR>> In between, there are interconnections of the many different<BR>> levels, such as semantic variations that may cause a puff of<BR>> white noise to be interpreted as different phonemes, depending<BR>> on what the listener was expecting.<BR>><BR>> I think that everybody who subscribes to this list would like<BR>> to see a simulator of all that. If anyone has such, please<BR>> let us know.<BR>><BR>> John Sowa<BR>><BR>><BR>><BR>><BR>> _______________________________________________<BR>> Corpora mailing list<BR>> <A href="mailto:Corpora@uib.no" ymailto="mailto:Corpora@uib.no">Corpora@uib.no</A><BR>> <A href="http://mailman.uib.no/listinfo/corpora" target=_blank>http://mailman.uib.no/listinfo/corpora</A><BR>><BR>><BR></DIV><BR></DIV></div></body></html>