1,721,055 research outputs found
Constructive negation and constraint logic programming with sets
No full textThe aim of this paper is to extend the Constructive Negation technique to the case of CLP(SET), a Constraint Logic Programming (CLP) language based on hereditarily (and hybrid) finite sets. The challenging aspects of the problem originate from the fact that the structure on which CLP(SET) is based is not admissible closed, and this does not allow to reuse the results presented in the literature concerning the relationships between CLP and constructive negation. We propose a new constraint satisfaction algorithm, capable of correctly handling constructive negation for large classes of CLP(SET) programs; we also provide a syntactic characterization of such classes of programs. The resulting algorithm provides a novel constraint simplification procedure to handle constructive negation, suitable to theories where unification admits multiple most general unifiers. We also show, using a general result, that it is impossible to construct an interpreter for CLP(SET) with constructive negation which is guaranteed to work for any arbitrary program; we identify classes of programs for which the implementation of the constructive negation technique is feasible
On the Representation and Management of Finite Sets in CLP-languages
No full textWe review and compare the main techniques considered to represent finite sets in logic languages. We present a technique that combines the benefits of the previous techniques, avoiding their drawbacks. We show how to verify satisfiability of any conjunction of (positive and negative) literals based on =, ⊆, ∈, and ∪, ∩, \, and ||, viewed as predicate symbols, in a (hybrid) universe of finite sets. We also show that ∪ and || (i.e., disjointness of two sets) are sufficient to represent all the above mentioned operations
Protein structure prediction on GPU: A declarative approach in a multi-Agent framework
No full textThis paper provides a novel perspective in the Protein Structure Prediction (PSP) problem. The PSP problem focuses on determining putative 3D structures of a protein starting from its primary sequence. The proposed approach relies on a multi-agents approach, where concurrent agents explore the folding of different parts of a protein. The strength of the approach lies in the agents' ability to apply different types of knowledge (expressed in the form of declarative constraints) to prune the local space of folding alternatives. The paper demonstrates the suitability of a GPU approach to implement such multi-agent infrastructure, with significant improvements in speed and quality of solutions w.r.t. other methods (e.g., based on fragments assembly approaches). © 2013 IEEE
- …
