We present a spectrum of default logics, using powerdoma~ns to encode default constraints. the resulting non-monotonic entailment relations all satisfy the law of reasoning by cases. this result is a consequence of tw...
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the Smodels system is a C++ implementation of the well-founded and stable model semantics for range-restricted function-free normal programs. the system includes two modules: (i) smodels which implements the two seman...
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ISBN:
(纸本)3540632557
the Smodels system is a C++ implementation of the well-founded and stable model semantics for range-restricted function-free normal programs. the system includes two modules: (i) smodels which implements the two semantics for ground programs and (ii) parse which computes a grounded version of a range-restricted function-free normal program. the latter module does not produce the whole set of ground instances of the program but a subset that is sufficient in the sense that no stable models ate lost. the implementation of the stable model semantics for ground programs is based on bottom-up backtracking search where a powerful pruning method is employed. the pruning method exploits an approximation technique for stable models which is closely related to the well-founded semantics. One of the advantages of this novel technique is that it can be implemented to work in linear space. this makes it possible to apply the stable model semantics also in areas where resulting programs are highly non-stratified and can possess a large number of stable models. the implementation has been tested extensively and compared with a state of the art implementation of the stable model semantics, the SLG system. In tests involving ground programs it clearly outperforms SLG.
We present a new method, called non-Horn magic sets (NHM), to enhance forward reasoning provers by combining top-down and bottom-up computations. this method is a natural extension of Horn magic sets and is applicable...
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ISBN:
(纸本)3540631046
We present a new method, called non-Horn magic sets (NHM), to enhance forward reasoning provers by combining top-down and bottom-up computations. this method is a natural extension of Horn magic sets and is applicable to range-restricted non-Horn clauses. We show two types of transformations to get non-Horn magic sees from the given clause sets: breadth-first NHM and depth-first NHM. the first transformation evaluates the antecedent atoms of an original clause in parallel. the second one evaluates them sequentially while propagating the bindings in an antecedent atom to the next by using continuation predicates. these transformations are shown to be sound and complete. the NHM method has been implemented on a UNIX workstation. We evaluated effects of NHM by proving some typical problems taken from the TPTP problem library.
We develop a logic for reasoning about object-oriented programs. the logic is for a language with an imperative semantics and aliasing, and accounts for self-reference in objects. It is much like a type system for obj...
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We propose a formal framework for functional logicprogramming, supporting lazy functions, non-determinism and polymorphic datatypes whose data constructors obey a given set C of equational axioms. On top of a given C...
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Ilf is a convenient interface between the non-expert user of ATP's and most of the available high performance ATP's. the typed first order input language and the transformation algorithms for coding types into...
ISBN:
(纸本)3540631046
Ilf is a convenient interface between the non-expert user of ATP's and most of the available high performance ATP's. the typed first order input language and the transformation algorithms for coding types into clausal logic, which are integrated into Ilf, make ATP's almost transparent to the user. One only has to learn one language to use many provers. the natural language proof presentation unit closes the gap between the (illegible) machine output of ATP's and the desire of the user to understand machine generated proofs. It is planned to upgrade all integrated ATP's as well as to integrate new high performance provers.
the proceedings contain 71 papers. the special focus in this conference is on Panel, Rewriting and Automata. the topics include: theoretical computer science and software science;future trends of TAPSOFT;new challenge...
ISBN:
(纸本)9783540627814
the proceedings contain 71 papers. the special focus in this conference is on Panel, Rewriting and Automata. the topics include: theoretical computer science and software science;future trends of TAPSOFT;new challenges for theoretical computer science;automata theory on trees and partial orders;a theory of testing for timed automata;conservative extensions, interpretations between theories and all that;specification and proof in membership equational logic;formalism and method;the common framework initiative for algebraic specification and development;logicality of conditional rewrite systems;simulating forward-branching systems with constructor systems;reliable generalized and context dependent commutation relations;word-into-trees transducers with bounded difference;generalized quantitative temporal reasoning;towards semantics of timed algorithms and their model-checking in high-level languages;model checking through symbolic reaehability graph;optimal implementation of wait-free binary relations;relative undecidability in the termination hierarchy of single rewrite rules;termination proofs using gpo ordering constraints;automatically proving termination where simplification orderings fail;generating efficient, terminating logic programs;modal characterization of weak bisimulation for higher-order processes;formats of ordered SOS rules with silent actions;a uniform syntactical method for proving coinduction principles in lambda-calculi;a labeued transition systems for pi-epsilon-calculus;set operations for recurrent term schematizations;inclusion constraints over non-empty sets of trees;grid structures and undecidable constraint theories;predicative functional recurrence and poly-space;on the complexity of function pointer may-alias analysis and maximum packing for biconnected outerptanar graphs.
Property theory, introduced in [Turner 87], is a classical first-order logicthat includes a . operator to turn propositions, properties and relations into terms. It is therefore an appropriate representation language...
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ISBN:
(纸本)3540631046
Property theory, introduced in [Turner 87], is a classical first-order logicthat includes a . operator to turn propositions, properties and relations into terms. It is therefore an appropriate representation language for intensional concepts such as knowledge and belief. the main advantage of Property theory over languages like Montague semantics is that it is a type-free language, and hence provides considerable extra expressive power. the pay-back is that it is consequently extremely intractable, and constructing an appropriate normal form has proven to be very difficult. [Ramsay 95] has already presented a preliminary model generation theorem prover for Property theory, based on the SATCHMO algorithm for. predicate calculus ([Manthey 88]). However, [Ramsay 95] does not construct a satisfactory normal form for Property theory. In this paper we examine and extend the model theory of Property theory and present a normal form based on our extension of Property theory. We conclude by outlining the role of our normal form in a model generation theorem prover for Property theory.
Several logics for reasoning under uncertainty distribute ''probability mass'' over sets in some sense. these include probabilistic logic, Dempster-Shafer theory, other logics based on belief functions...
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Several logics for reasoning under uncertainty distribute ''probability mass'' over sets in some sense. these include probabilistic logic, Dempster-Shafer theory, other logics based on belief functions, and second-order probabilistic logic. We show that these logics are instances of a certain type of linear programming model, typically with exponentially many variables. We also show how a single linear programming package can implement these logics computationally if one ''plugs in'' a different column generation subroutine for each logic, although the practicality of this approach has been demonstrated so far only for probabilistic logic.
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