Originally proposed in the mid-90s, design patterns for software development played a key role in objectoriented programming not only in increasing software quality, but also by giving a better understanding of the po...
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Many programs have an inherently reactive nature imposed by the functional dependencies between their data and external events. Classically, these dependencies are dealt with using callbacks. Reactive programming with...
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ISBN:
(纸本)9781450328685
Many programs have an inherently reactive nature imposed by the functional dependencies between their data and external events. Classically, these dependencies are dealt with using callbacks. Reactive programming with first-class reactive values is a paradigm that aims to encode callback logic in declarative statements. Reactive values concisely define dependencies between singular data elements, but cannot efficiently express dependencies in larger datasets. Orthogonally, embedding reactive values in a shared-memory concurrency model convolutes their semantics and requires synchronization. this paper presents a generic framework for reactive programmingthat extends first-class reactive values withthe concept of lazy reactive containers, backed by several concrete implementations. Our framework addresses concurrency by introducing reactive isolates. We show examples that our programming model is efficient and convenient to use.
A series of recent papers introduces a coalgebraic semantics for logicprogramming, where the behavior of a goal is represented by a parallel model of computation called coinductive tree. this semantics fails to be co...
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Most of the DNA Sequence Alignment methods are mostly based on dynamic programming algorithms with low efficiency and poor accuracy. For these deficiencies, a new method is presented. this method is based on the Boole...
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the proceedings contain 15 papers. the special focus in this conference is on Mathematics of Program Construction. the topics include: Integrating programming, properties, and validation;polytypic values possess polyk...
ISBN:
(纸本)9783540677277
the proceedings contain 15 papers. the special focus in this conference is on Mathematics of Program Construction. the topics include: Integrating programming, properties, and validation;polytypic values possess polykinded types;the zip calculus;separation and reduction;reasoning about non-terminating loops using deadline commands;quantum programming;a coinductive approach to streams, automata, and power series;proving pointer programs in hoare logic;on guarded commands with fair choice;formal methods and dependability;liberating data refinement;theorems about composition;the universal resolving algorithm;metacomputation-based compiler architecture;a metalanguage for programming with bound names modulo renaming.
We propose an approach for single-agent epistemic planning in domains with incomplete knowledge. We argue that on the one hand the integration of epistemic reasoning into planning is useful because it makes the use of...
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ISBN:
(纸本)9789898565389
We propose an approach for single-agent epistemic planning in domains with incomplete knowledge. We argue that on the one hand the integration of epistemic reasoning into planning is useful because it makes the use of sensors more flexible. On the other hand, defining an epistemic problem description is an error prone task as the epistemic effects of actions are more complex than their usual physical effects. We apply the axioms of the Discrete Event Calculus Knowledge theory (DECKT) as rules to compile simple non-epistemic planning problem descriptions into complex epistemic descriptions. We show how the resulting planning problems are solved by our implemented prototype which is based on Answer Set programming (ASP).
the notion of independence has been used in conventional logicprogramming as the basis for several optimizations, including program parallelization, intelligent backtracking, and goal reordering. In this paper we ext...
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We introduce choice logic programs as negation-free datalog programs that allow rules to have exclusive-only (possibly empty) disjunctions in the head. Such programs naturally model decision problems where, depending ...
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ISBN:
(纸本)3540667490
We introduce choice logic programs as negation-free datalog programs that allow rules to have exclusive-only (possibly empty) disjunctions in the head. Such programs naturally model decision problems where, depending on a context, agents must make a decision, i.e. an exclusive choice out of several alternatives. It is shown that such a choice mechanism is in a sense equivalent with negation as supported in semi-negative ("normal") datalog programs. We also discuss an application where strategic games can be naturally formulated as choice programs: it turns out that the stable models of such programs capture exactly the set of Nash equilibria. We then consider the effect of choice on "negative information" that may be implicitly derived from a program. Based on an intuitive notion of unfounded set for choice programs. ive show that several results from (seminegative) disjunctive programs can be strengthened;characterizing the position of choice programs as an intermediate between simple positive programs and programs that allow for the explicit use of negation in the body of a rule.
Data standardization is the commercially important process of extracting useful information from poorly structured textual data. this process includes correcting misspellings and truncations, extraction of data via pa...
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ISBN:
(纸本)3540667490
Data standardization is the commercially important process of extracting useful information from poorly structured textual data. this process includes correcting misspellings and truncations, extraction of data via parsing, and correcting inconsistencies in extracted data. Prolog programming offers natural advantages for standardizing: definite clause grammars can be used to parse data;Prolog rules can be used to correct inconsistencies;and Prolog's simple syntax allows rules to be generated to correct misspellings and truncations of keywords. these advantages can be seen as rudimentary mechanisms for knowledge representation and at least one commercial standardizer has exploited these advantages. However advances in implementation and in knowledge representation - in particular the addition of preferences to logical formalisms - allow even more powerful and declarative standardizers to be constructed. In this paper a simple preference logic, that of [7] is considered. A fixed point semantics is defined for this logic and its tabled implementation within XSB is described. Development of a commercial standardizer using the preference logic of [7] is then documented. Finally, detailed comparisons are made between the preference logic standardizer and the previous Prolog standardizer illustrating how an advance in knowledge representation can lead to improved commercial software.
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