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## Re: [ontolog-forum] HOL decidability [Was: using SKOSforcontrolledvalues

 To: "[ontolog-forum]" Pavithra Fri, 15 Oct 2010 06:48:54 -0700 (PDT) <523713.66545.qm@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
 In computer science, an iterator is an object that allows a programmer to traverse through all the elements of a collection, regardless of its specific implementation. An iterator is sometimes called a cursor, especially within the context of a database.--- On Fri, 10/15/10, Rich Cooper wrote:From: Rich Cooper Subject: Re: [ontolog-forum] HOL decidability [Was: using SKOSforcontrolledvalues for controlledvocabulary]To: "'[ontolog-forum] '" Date: Friday, October 15, 2010, 9:36 AMInfinite precision arithmetic repeatedly adds another computer word torepresent numbers that overflow with the current number of words.  You weretalking about carries propagating across a word, remember?  So if you add 1to 2^32-1, you get a two word number in 64 bits instead of a one word numberin 32 bits, and the execution time is no longer linear.  The number keepsgetting bigger as needed to represent the new value, adding one word ofprecision as needed.  That makes it recursive in the sense of precisionrepresentation; there is no end to the number of such words that can beadded on overflow.  That is what makes it recursive, and that is what makesit increasing in time and space consumption.  But an iterator, by my definition, for good practice, must not be recursivein that it is must take a fixed time and space consumption during operation,otherwise the time and space are not linear for each execution of theiterator.  Recursive calls to the same function results in an unlimitedexpense in time and space, and therefore is not good practice for aniterator.  Math is ideal in its behavior; computers aren't.  So a recursivefunction is not an iterator in my sense of that word.  Translate to your ownmethod of expressing that fact to get the point.  -Rich Sincerely,Rich CooperEnglishLogicKernel.comRich AT EnglishLogicKernel DOT com9 4 9 \ 5 2 5 - 5 7 1 2-----Original Message-----From: ontolog-forum-bounces@xxxxxxxxxxxxxxxx[mailto:ontolog-forum-bounces@xxxxxxxxxxxxxxxx] On Behalf Of Randall RSchulzSent: Thursday, October 14, 2010 9:34 PMTo: [ontolog-forum] Subject: Re: [ontolog-forum] HOL decidability [Was: usingSKOSforcontrolledvalues for controlledvocabulary]On Thursday October 14 2010, Rich Cooper wrote:> There is a version of Lisp which incorporates infinite precision> arithmetic. You might find an iterator of the kind you are looking> for there.That is a complete nonsequitur. My point is that your criterion about the absence of an underlying iterative process for something to be iterative cannot be met. Switching to infinite-precision arithmetic does not make that go away, it just makes it unbounded.Computing the successor of the following number (shown in binary): 11111111111111111111111111111111111111111111111111on a contemporary computer that uses binary representation of integers will require 60 iterations of its carry algorithm. So the INC instruction (as well as ADD, MUL, DIV and all the other arithmetic operations defined by that processor) of necessity invoke underlying iterative processes. So by your criterion, it is impossible to realize an iteration on such a processor.> ....>> -RichRandall Schulz _________________________________________________________________Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/  Config Subscr: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/  Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxxShared Files: http://ontolog.cim3.net/file/Community Wiki: http://ontolog.cim3.net/wiki/ To join: http://ontolog.cim3.net/cgi-bin/wiki.pl?WikiHomePage#nid1JTo Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx _________________________________________________________________Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/  Config Subscr: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/  Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxxShared Files: http://ontolog.cim3.net/file/Community Wiki: http://ontolog.cim3.net/wiki/ To join: http://ontolog.cim3.net/cgi-bin/wiki.pl?WikiHomePage#nid1JTo Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx

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