Re: beginner's question: Difference between CWA and NAF

with "NAF => CWA" ,I mean :
"if one can suppose, that NAF leads to a correct interpretation of
negation then one can conclude the assumptions made by CWA"

Another way to say it : If you tell someone, who never heard anything
about CWA and NAF, that he can get the value of "not q(X)" in
p(X) :- s(X,Y), not q(X)
by checking all positive substitutes given by that s-literal in q to be
stored (or been proven in Prolog)
ie: let a positive substitution given by s , say X=a
if q(a) is proven(/stored), then "not q(a)" is wrong and if it's not,
then "not q(a)" is true.

With this rule of evaluation one should conclude the assumptions of the
CWA.

I guess i am wrong, but I don't see why at the moment.

Perhaps someone could give me an exact definition (for both: CWA and
NAF) first ?

thx for your help !

.

Relevant Pages

  • Re: beginners question: Difference between CWA and NAF
    ... I wrote NFA twice instead of NAF:-! ... > CWA deals mostly with theory, ... > This is done mostly to avoid Prolog's infinite loops. ...
    (comp.lang.prolog)
  • Re: beginners question: Difference between CWA and NAF
    ... CWA, also called "negation as infinite failure", is a ... notion of CWA in which "false" means FINITELY failed. ... but cannot be concluded by NAF (the SLD-tree is ... > negation then one can conclude the assumptions made by CWA" ...
    (comp.lang.prolog)
  • Re: beginners question: Difference between CWA and NAF
    ... CWA deals mostly with theory, ... issues have to be modified to be implemented in Prolog. ... This is done mostly to avoid Prolog's infinite loops. ... > But how can NAF work when only using a top-down SLD-tree? ...
    (comp.lang.prolog)
  • Re: beginners question: Difference between CWA and NAF
    ... > notion of CWA in which "false" means FINITELY failed. ... facts of f can be found by a bottom-up progress like fixpoint ... Of course - like you said: CWA is used to compute all provable facts. ... But how can NAF work when only using a top-down SLD-tree? ...
    (comp.lang.prolog)