On 10/6/07, Edward W. Porter <[EMAIL PROTECTED]> wrote: > > > > So is the following understanding correct? > > > If you have two statements > > > Fred is a human > Fred is an animal > > And assuming you know nothing more about any of the three terms in both > these statements, then each of the following would be an appropriate > induction > > > A human is an animal > An animal is a human > A human and an animal are similar
Correct, though for technical reasons I don't call the last one "induction" but "comparison". > It would only then be from further information that you would find the first > of these two inductions has a larger truth value than the second and that > the third probably has a larger truth value than the second.. Right, though the rules immediately assigns truth values to the conclusion, based on the evidence provided by the current premises. The role of "further information" is to revise the previous truth values. In this way, the system can always form a belief (rather than waiting for "enough information"), though the initial beliefs will have low confidence. Pei > Edward W. Porter > Porter & Associates > 24 String Bridge S12 > Exeter, NH 03833 > (617) 494-1722 > Fax (617) 494-1822 > [EMAIL PROTECTED] > > > > -----Original Message----- > From: Pei Wang [mailto:[EMAIL PROTECTED] > Sent: Saturday, October 06, 2007 7:03 AM > To: agi@v2.listbox.com > Subject: Re: [agi] Do the inference rules of categorical logic make sense? > > > > Right. See concrete examples in > http://nars.wang.googlepages.com/NARS-Examples-SingleStep.txt > > In induction and abduction, S-->P and P-->S are usually (though not > always) produced in pair, though usually (though not always) with different > truth values, unless the two premises have the same truth-value --- as > Edward said, it would be illogical to produce difference from sameness. ;-) > > Especially, positive evidence equally support both conclusions, while > negative evidence only deny one of the two --- see the "Induction and > Revision" example in > http://nars.wang.googlepages.com/NARS-Examples-MultiSteps.txt > > For a more focused discussion on induction in NARS, see > http://www.cogsci.indiana.edu/pub/wang.induction.ps > > The situation for S<->P is similar --- see "comparison" in > http://nars.wang.googlepages.com/NARS-Examples-SingleStep.txt > > Pei > > On 10/6/07, Lukasz Stafiniak <[EMAIL PROTECTED]> wrote: > > Major premise and minor premise in a syllogism are not > > interchangeable. Read the derivation of truth tables for abduction and > > induction from the semantics of NAL to learn that different ordering > > of premises results in different truth values. Thus while both > > orderings are applicable, one will usually give more confident result > > which will dominate the other. > > > > On 10/6/07, Edward W. Porter <[EMAIL PROTECTED]> wrote: > > > > > > > > > But I don't understand the rules for induction and abduction which > > > are as > > > following: > > > > > > ABDUCTION INFERENCE RULE: > > > Given S --> M and P --> M, this implies S --> P to some degree > > > > > > INDUCTION INFERENCE RULE: > > > Given M --> S and M --> P, this implies S --> P to some degree > > > > > > The problem I have is that in both the abduction and induction rule > > > -- unlike in the deduction rule -- the roles of S and P appear to be > > > semantically identical, i.e., they could be switched in the two > > > premises with no apparent change in meaning, and yet in the > > > conclusion switching S and P would change in meaning. Thus, it > > > appears that from premises which appear to make no distinctions > > > between S and P a conclusion is drawn that does make such a > > > distinction. At least to me, with my current limited knowledge of > > > the subject, this seems illogical. > > > > ----- > > This list is sponsored by AGIRI: http://www.agiri.org/email To > > unsubscribe or change your options, please go to: > > http://v2.listbox.com/member/?&; > > > > > > ----- > This list is sponsored by AGIRI: http://www.agiri.org/email > To unsubscribe or change your options, please go to: > http://v2.listbox.com/member/?&; ________________________________ > This list is sponsored by AGIRI: http://www.agiri.org/email > To unsubscribe or change your options, please go to: > http://v2.listbox.com/member/?&; ----- This list is sponsored by AGIRI: http://www.agiri.org/email To unsubscribe or change your options, please go to: http://v2.listbox.com/member/?member_id=8660244&id_secret=50768597-1784af
