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/?member_id=8660244&id_secret=50765665-44f7f5
