In this paper, we expose the use of CLP in a Textual Data Mining Task. Text Mining process is here applied to a corpus of semi-structured documents like seminary and job announcement. Such documents contain semi-struc...
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ISBN:
(纸本)354029208X
In this paper, we expose the use of CLP in a Textual Data Mining Task. Text Mining process is here applied to a corpus of semi-structured documents like seminary and job announcement. Such documents contain semi-structured sections each of which will be recognised by an automaton whose language is characterised by a set of CLP rules.
We consider automated reasoning about recursive partial functions with decidable domain, i.e. functions computed by incompletely defined but terminating functional programs. Incomplete definitions provide an elegant a...
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ISBN:
(纸本)354030553X
We consider automated reasoning about recursive partial functions with decidable domain, i.e. functions computed by incompletely defined but terminating functional programs. Incomplete definitions provide an elegant and easy way to write and to reason about programs which may halt with a run time error by throwing an exception or printing an error message, e.g. when attempting to divide by zero. We investigate the semantics of incompletely defined programs, define an interpreter for those programs and discuss the termination of incompletely defined procedures. We then analyze which problems need to be solved if a theorem prover designed for verification of completely defined programs is modified to work for incompletely defined programs as well. We also discuss how to reason about stuck computations which arise when calling incompletely defined procedures with invalid arguments. Our method of automated reasoning about incompletely defined programs has been implemented in the verification tool VeriFun. We conclude by discussing experiences obtained in several case studies with this implementation and also compare and relate our proposal to other work.
We propose an operational framework which builds on the classical understanding of abductive reasoning in logic programming, and extends it in several directions. The new features include the ability to reason with a ...
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ISBN:
(纸本)3540290419
We propose an operational framework which builds on the classical understanding of abductive reasoning in logic programming, and extends it in several directions. The new features include the ability to reason with a dynamic knowledge base, where new facts can be added anytime, the ability to generate expectations about such new facts occurring in the future (forecasting), and the process of confirmation/disconfirmation of such expectations.
We consider the problem of identifying equivalence of two knowledge bases which are capable of abductive reasoning. Here, a knowledge base is written in either first-order logic or nonmonotonic logic programming. In t...
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We consider the problem of identifying equivalence of two knowledge bases which are capable of abductive reasoning. Here, a knowledge base is written in either first-order logic or nonmonotonic logic programming. In this work, we will give two definitions of abductive equivalence. The first one, explainable equivalence, requires that two abductive programs have the same explainability for any observation. Another one, explanatory equivalence, guarantees that any observation has exactly the same explanations in each abductive framework. Explanatory equivalence is a stronger notion than explainable equivalence. In first-order abduction, explainable equivalence can be verified by the notion of extensional equivalence in default theories. In nonmonotonic logic programs, explanatory equivalence can be checked by means of the notion of relative strong equivalence. We also show the complexity results for abductive equivalence.
We introduce Abstract DPLL, a general and simple abstract rule-based formulation of the Davis-Putnam-Logemann-Loveland (DPLL) procedure. Its properties, such as soundness, completeness or termination, immediately carr...
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ISBN:
(纸本)3540252363
We introduce Abstract DPLL, a general and simple abstract rule-based formulation of the Davis-Putnam-Logemann-Loveland (DPLL) procedure. Its properties, such as soundness, completeness or termination, immediately carry over to the modern DPLL implementations with features such as non-chronological backtracking or clause learning. This allows one to formally reason about practical DPLL algorithms in a simple way. In the second part of this paper we extend the framework to Abstract DPLL modulo theories. This allows us to express-and formally reason about-state-of-the-art concrete DPLL-based techniques for satisfiability modulo background theories, such as the different lazy approaches, or our DPLL(T) framework.
We present a simple, yet general top-down query answering procedure for normal logic programs over lattices and bilattices, where functions may appear in the rule bodies. Its interest relies on the fact that many appr...
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ISBN:
(纸本)3540273263
We present a simple, yet general top-down query answering procedure for normal logic programs over lattices and bilattices, where functions may appear in the rule bodies. Its interest relies on the fact that many approaches to para-consistency and uncertainty in logic programs with or without non-monotonic negation are based on bilattices or lattices, respectively.
Nominal logic is a variant of first-order logic with special facilities for reasoning about names and binding based on the underlying concepts of swapping and freshness. It serves as the basis of logic programming and...
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ISBN:
(纸本)3540255966
Nominal logic is a variant of first-order logic with special facilities for reasoning about names and binding based on the underlying concepts of swapping and freshness. It serves as the basis of logic programming and term rewriting techniques that provide similar advantages to, but remain simpler than, higher-order logic programming or term rewriting systems. Previous work on nominal rewriting and logic programming has relied on nominal unification, that is, unification up to equality in nominal logic. However, because of nominal logic's equivariance property, these applications require a stronger form of unification, which we call equivariant unification. Unfortunately, equivariant unification and matching are NP-hard decision problems. This paper presents an algorithm for equivariant unification that produces a complete set of finitely many solutions, as well as NP decision procedure and a version that enumerates solutions one at a time. In addition, we present a polynomial time algorithm for swapping-free equivariant matching, that is, for matching problems in which the swapping operation does not appear.
PROB is a model checking tool for the B Method. In this paper we present an extension of PRoB that supports checking of specifications written in a combination of CSP and B. We explain how the notations are combined s...
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ISBN:
(纸本)3540278826
PROB is a model checking tool for the B Method. In this paper we present an extension of PRoB that supports checking of specifications written in a combination of CSP and B. We explain how the notations are combined semantically and give an overview of the implementation of the combination. We illustrate the benefit that appropriate use of CSP, in conjunction with our tool, gives to B developments both for specification and for verification purposes.
The paper presents DLV(+)a Disjunctive logic programming system with object-oriented constructs, including classes, objects, (multiple) inheritance, and types. DLV+ is built on top of DLV (a state-of-the art DLP syste...
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ISBN:
(纸本)3540285385
The paper presents DLV(+)a Disjunctive logic programming system with object-oriented constructs, including classes, objects, (multiple) inheritance, and types. DLV+ is built on top of DLV (a state-of-the art DLP system), and provides a graphical user interface that allows to specify, update, browse, query, and reason on knowledge bases. Two strong points of the system are the powerful type-checking mechanism, and the advanced interface for visual querying.
One first defines the triangles of a lattice T, that is, the lattices Delta(s)(T) of all decreasing sequences of s elements of T, and study some basic properties (modularity, distributivity, boundedness, atomisticity,...
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ISBN:
(纸本)0769523366
One first defines the triangles of a lattice T, that is, the lattices Delta(s)(T) of all decreasing sequences of s elements of T, and study some basic properties (modularity, distributivity, boundedness, atomisticity, inf-pseudo complementation, monotonic representations) of Delta(s)(T). An important result is : If T is a boolean algebra, then Delta S(T) is a Post algebra (of order (s+1));one specially discusses the case when T is the powerset P(Omega) : Delta(s)(T) is then isomorphic to the postian lattice Ps+1(Omega) of the (s+1)-ordered partitions of Omega which is a multivalued genereralization of the powerset. Afterwards, one studies some cases where T is, in turn, a Post algebra, specially T = P-r(Omega)). One then exhibits some typical finite distributive lattices called leibnizians, denoted < r + s(s) - 1 > and also defines, with the help of triangulation, the lattices P-s,P-r(Omega) which arle called the postians of type (s,r) of a set Omega. Actually both structures (leibnizians as well as postians) turn out to be important algebraic concretisations of Post multivalued logical conceptions.
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