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## Re: [ontolog-forum] Re Foundation ontology, CYC, and Mapping

 To: ontolog-forum@xxxxxxxxxxxxxxxx "John F. Sowa" Tue, 30 Mar 2010 20:03:51 -0500 <4BB29F77.3070005@xxxxxxxxxxx>
 Rich and Chris,    (01) RC> Actually, Nand and Nor logic is no more complex than And and Or > logic, in my opinion. I used it extensively in digital circuit > design once upon a time and never noticed any inconvenience or > confusion at all.    (02) Yes, I said that it was useful for reducing the number of transistors in logic circuits. For that purpose, it would indeed be "simpler".    (03) But several different choices of axioms and primitives would produce identical theories of Boolean algebra. For applications, the choice of primitives would be irrelevant, since all 16 Boolean operators of two inputs would be definable in any of the theories    (04) CM> It is simply a greater conceptual challenge to master and work > exclusively with Nand and Nor than with and, or, and not.    (05) I agree. There are good reasons why natural languages have the equivalents of And, Or, Not, If-then, Some, & Every:    (06) 1. Any observational statement can be expressed with just two operators: And, Some.    (07) 2. All other operators (Or, Not, If-then, Every, Nand, Nor) can only be inferred, not observed directly.    (08) 3. To deny something, you need Not. To state alternatives, you need Or. For causality, you need If-then. For generality, you need Every.    (09) 4. But Nand & Nor are even farther removed from observation. They require two steps: an inference plus a denial.    (010) RC> Why pick either one unless it's for a specific task, chosen > for a specific person's utility in carrying out that task?    (011) I agree that different options may be useful for different applications, and we should support as broad a range as possible. Sometimes (as for Nand & Nor) those options come "for free" with many different choices of primitives.    (012) In any case, I should have chosen Turing machines to illustrate the point that simplicity in the primitives might not make the complete system simpler. Very few people would be happy to replace their programming languages with Turing machines.    (013) But all this discussion supports my main point:    (014) The question of what makes something simple is not simple.    (015) John    (016) _________________________________________________________________ Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/ Config Subscr: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/ Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx Shared Files: http://ontolog.cim3.net/file/ Community Wiki: http://ontolog.cim3.net/wiki/ To join: http://ontolog.cim3.net/cgi-bin/wiki.pl?WikiHomePage#nid1J To Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx    (017)
 Current Thread Re: [ontolog-forum] Re Foundation ontology, CYC, and Mapping, (continued) Re: [ontolog-forum] Re Foundation ontology, CYC, and Mapping, John F. Sowa Re: [ontolog-forum] Re Foundation ontology, CYC, and Mapping, Christopher Menzel Re: [ontolog-forum] Re Foundation ontology, CYC, and Mapping, John F. Sowa Re: [ontolog-forum] Re Foundation ontology, CYC, and Mapping, Christopher Menzel Re: [ontolog-forum] Re Foundation ontology, CYC, and Mapping, Rich Cooper Re: [ontolog-forum] Re Foundation ontology, CYC, and Mapping, Christopher Menzel Re: [ontolog-forum] Re Foundation ontology, CYC, and Mapping, Cameron Ross Re: [ontolog-forum] Re Foundation ontology, CYC, and Mapping, Rich Cooper Re: [ontolog-forum] Re Foundation ontology, CYC, and Mapping, Christopher Menzel Re: [ontolog-forum] Re Foundation ontology, CYC, and Mapping, Rich Cooper Re: [ontolog-forum] Re Foundation ontology, CYC, and Mapping, John F. Sowa <= Re: [ontolog-forum] Re Foundation ontology, CYC, and Mapping, Kevin D Keck Re: [ontolog-forum] Re Foundation ontology, CYC, and Mapping, Mike Bennett Re: [ontolog-forum] Re Foundation ontology, CYC, and Mapping, David Leal Re: [ontolog-forum] Re Foundation ontology, CYC, and Mapping, sowa