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Technical Reports |
2001 | 2002 | 2003 | 2005 | 2007 | 2008 |
| NMSU-CS-2008-001 |
| Credulous Resolution for Answer Set Programming |
| Piero A. Bonatti, Enrico Pontelli, Tran Cao Son |
| Abstract: The paper presents a calculus based on resolution for credulous reasoning in Answer Set Programming. The new approach allows a top-down and goal directed resolution, in the same spirit as traditional SLD-resolution. The proposed credulous resolution can be used in query-answering with nonground queries and with non-ground, and possibly infinite, programs. Soundness and completeness results for the resolution procedure are proved for large classes of logic programs. The resolution procedure is also extended to handle some traditional syntactic extensions used in Answer Set Programming, such as choice rules and constraints. The paper also describes an initial implementation of a system for credulous reasoning in Answer Set Programming. |
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| NMSU-CS-2008-002 |
| Computing Approximate Solutions of the Protein Structure Determination Problem using Global Constraints on Discrete Crystal Lattices |
| A. Dal Palu', A. Dovier, E. Pontelli |
| Abstract: Crystal lattices are discrete models of the three-dimensional space that have been effectively employed to facilitate the task of determining proteins' natural conformation. This paper investigates alternative global constraints that can be introduced in a constraint solver over discrete crystal lattices. The objective is to enhance the efficiency of lattice solvers in dealing with the construction of approximate solutions of the protein structure determination problem. Some of them (e.g., self-avoiding-walk) have been explicitly or implicitly already used in previous approaches, while others (e.g., the density constraint) are new. The intrinsic complexities of all of them are studied and preliminary experimental results are discussed. |
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