CMU Artificial Intelligence Repository
 
   
   
   
   
  
NATHAN (Spec13): Argues defeasibly in first-order logic.
areas/reasonng/defeasbl/nathan/
Nathan (specs1-13) is a relatively fast implementation of a defeasible
reasoner with specificity.  It uses arguments of the kind described in
[1,2] and its specificity comparator (LMNOP) is described in [3] which
is a modification of the criterion of Poole.
It solves all basic benchmark problems to the author's satisfaction.
Its limitations in planning applications are due to the limits of its
underlying resolution-refutation linear-input set-of-support
theorem-prover for FOL.
It includes a predicate for unique names.  It includes a perl
preprocessor for extracting rules from cases.
Origin:   
   Email from R. Loui.
Version:      19-FEB-94
Requires:     C
Copying:      Copyright (c) 1994 by R. Loui.
              Use, copying, and distribution permitted, provided that
              NATHAN (and derivatives) are not included in a
              commercial product.
CD-ROM:       Prime Time Freeware for AI, Issue 1-1
Mailing List: None
Author(s):    R. Loui, A. Costello, A. Merrill
Contact:      Dr. R. P. Loui 
              Dept. of Computer Science
              Washington University
              St. Louis, MO  63130
              Tel: 314-935-6102
Keywords:
   Argument, Authors!Costello, Authors!Loui, Authors!Merrill, 
   C!Code, Defeasible Reasoning, Dialectic, Inheritance, NATHAN, 
   Nonmonotonic Reasoning, Planning, 
   Reasoning!Defeasible Reasoning, 
   Reasoning!Nonmonotonic Reasoning, Specificity
References:
   A user's manual and typescript may be found at the top of the
   source code. 
   
   Other relevant references include:
   
      [1] Loui, R. P., "A system of defeasible inference", COMPUTATIONAL
          INTELLIGENCE 3, 1987. 
   
      [2] Simari, G.R., and Loui, R.P., "Mathematics of defeasible
          reasoning", ARTIFICIAL INTELLIGENCE 53, 1992. 
   
      [3] R.P. Loui, J. Norman, Andrew Merrill, J. Olson, Q. Stiefvater, and
          Adam M. Costello, "Computing specificity", Washington University
          CS Technical Report 93-03, 1993.
Last Web update on Mon Feb 13 10:27:48 1995 
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