This paper studies the relation between two recent extensions of propositional Equilibrium logic, a well-known logical characterisation of Answer Set programming. In particular, we show how Temporal Equilibrium logic,...
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This paper studies the relation between two recent extensions of propositional Equilibrium logic, a well-known logical characterisation of Answer Set programming. In particular, we show how Temporal Equilibrium logic, which introduces modal operators as those typically handled in Linear-Time Temporal logic (LTL), can be encoded into Infinitary Equilibrium logic, a recent formalisation that allows the use of infinite conjunctions and disjunctions. We prove the correctness of this encoding and, as an application, we further use it to show that the semantics of the temporal logicprogramming formalism called TEMPLOG is subsumed by Temporal Equilibrium logic.
Propositional formulas that are equivalent in intuitionistic logic, or in its extension known as the logic of here-and-there, have the same stable models. We extend this theorem to propositional formulas with infinite...
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Propositional formulas that are equivalent in intuitionistic logic, or in its extension known as the logic of here-and-there, have the same stable models. We extend this theorem to propositional formulas with infinitely long conjunctions and disjunctions and show how to apply this generalization to proving properties of aggregates in answer set programming.
This paper introduces a new logic-based method for optimising the selection of compiler flags on embedded architectures. In particular, we use Inductive logicprogramming (ILP) to learn logical rules that relate effec...
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This paper introduces a new logic-based method for optimising the selection of compiler flags on embedded architectures. In particular, we use Inductive logicprogramming (ILP) to learn logical rules that relate effective compiler flags to specific program features. Unlike earlier work, we aim to infer human-readable rules and we seek to develop a relational first-order approach which automatically discovers relevant features rather than relying on a vector of predetermined attributes. To this end we generated a data set by measuring execution times of 60 benchmarks on an embedded system development board and we developed an ILP prototype which outperforms the current state-of-the-art learning approach in 34 of the 60 benchmarks. Finally, we combined the strengths of the current state of the art and our ILP method in a hybrid approach which reduced execution times by an average of 8% and up to 50% in some cases.
Tabling is probably the most widely studied extension of Prolog. But despite its importance and practicality, tabling is not implemented by most Prolog systems. Existing approaches require substantial changes to the P...
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Tabling is probably the most widely studied extension of Prolog. But despite its importance and practicality, tabling is not implemented by most Prolog systems. Existing approaches require substantial changes to the Prolog engine, which is an investment out of reach of most systems. To enable more widespread adoption, we present a new implementation of tabling in under 600 lines of Prolog code. Our lightweight approach relies on delimited control and provides reasonable performance.
There is a growing need for abstractions in logic specification languages such as FO(.) and ASP. One technique to achieve these abstractions are templates (sometimes called macros). While the semantics of templates ar...
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There is a growing need for abstractions in logic specification languages such as FO(.) and ASP. One technique to achieve these abstractions are templates (sometimes called macros). While the semantics of templates are virtually always described through a syntactical rewriting scheme, we present an alternative view on templates as second order definitions. To extend the existing definition construct of FO(.) to second order, we introduce a powerful compositional framework for defining logics by modular integration of logic constructs specified as pairs of one syntactical and one semantical inductive rule. We use the framework to build a logic of nested second order definitions suitable to express templates. We show that under suitable restrictions, the view of templates as macros is semantically correct and that adding them does not extend the descriptive complexity of the base logic, which is in line with results of existing approaches.
Fuzzy answer set programming (FASP) combines two declarative frameworks, answer set programming and fuzzy logic, in order to model reasoning by default over imprecise information. Several connectives are available to ...
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Fuzzy answer set programming (FASP) combines two declarative frameworks, answer set programming and fuzzy logic, in order to model reasoning by default over imprecise information. Several connectives are available to combine different expressions;in particular the Godel and Lukasiewicz fuzzy connectives are usually considered, due to their properties. Although the Godel conjunction can be easily eliminated from rule heads, we show through complexity arguments that such a simplification is infeasible in general for all other connectives. The paper analyzes a translation of FASP programs into satisfiability modulo theories (SMT), which in general produces quantified formulas because of the minimality of the semantics. Structural properties of many FASP programs allow to eliminate the quantification, or to sensibly reduce the number of quantified variables. Indeed, integrality constraints can replace recursive rules commonly used to force Boolean interpretations, and completion subformulas can guarantee minimality for acyclic programs with atomic heads. Moreover, head cycle free rules can be replaced by shifted subprograms, whose structure depends on the eliminated head connective, so that ordered completion may replace the minimality check if also Lukasiewicz disjunction in rule bodies is acyclic. The paper also presents and evaluates a prototype system implementing these translations.
The supertree construction problem is about combining several phylogenetic trees with possibly conflicting information into a single tree that has all the leaves of the source trees as its leaves and the relationships...
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The supertree construction problem is about combining several phylogenetic trees with possibly conflicting information into a single tree that has all the leaves of the source trees as its leaves and the relationships between the leaves are as consistent with the source trees as possible. This leads to an optimization problem that is computationally challenging and typically heuristic methods, such as matrix representation with parsimony (MRP), are used. In this paper we consider the use of answer set programming to solve the supertree construction problem in terms of two alternative encodings. The first is based on an existing encoding of trees using substructures known as quartets, while the other novel encoding captures the relationships present in trees through direct projections. We use these encodings to compute a genus-level supertree for the family of cats (Felidae). Furthermore, we compare our results to recent supertrees obtained by the MRP method.
The proceedings contain 25 papers. The special focus in this conference is on Concurrent and Distributed Systems. The topics include: The death of object-oriented programming;automated choreography repair;a graph-base...
ISBN:
(纸本)9783662496640
The proceedings contain 25 papers. The special focus in this conference is on Concurrent and Distributed Systems. The topics include: The death of object-oriented programming;automated choreography repair;a graph-based semantics workbench for concurrent asynchronous programs;a formal framework for modeling hadoop YARN clusters;integrated environment for verifying and running distributed components;iterative and incremental model generation by logic solvers;automated model merge by design space exploration;automatic construction of variability-based model transformation rules;two-step transformation of model traversal EOL queries for large CDO repositories;cut branches before looking for bugs;the influences of edge instability on change propagation and connectivity in call graphs;modeling and abstraction of memory management in a hypervisor;crowdsourced bug triaging;model-based testing of probabilistic systems;an iterative decision-making scheme for markov decision processes and its application to self-adaptive systems;family-based modeling and analysis for probabilistic systems;statistical model checking of e-motions domain-specific modeling languages;towards formal proof metrics;reduction rules for colored workflow nets;many-valued institutions for constraint specification;a cafeOBJ interpreter in maude;on the formal correctness of an LTS transformation verification technique;hybrid session verification through endpoint API generation and partial variable assignment interpolatoR.
This paper describes Picat's planner, its implementation, and planning models for several domains used in International Planning Competition (IPC) 2014. Picat's planner is implemented by use of tabling. During...
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This paper describes Picat's planner, its implementation, and planning models for several domains used in International Planning Competition (IPC) 2014. Picat's planner is implemented by use of tabling. During search, every state encountered is tabled, and tabled states are used to effectively perform resource-bounded search. In Picat, structured data can be used to avoid enumerating all possible permutations of objects, and term sharing is used to avoid duplication of common state data. This paper presents several modeling techniques through the example models, ranging from designing state representations to facilitate data sharing and symmetry breaking, encoding actions with operations for efficient precondition checking and state updating, to incorporating domain knowledge and heuristics. Broadly, this paper demonstrates the effectiveness of tabled logicprogramming for planning, and argues the importance of modeling despite recent significant progress in domain-independent PDDL planners.
This book is a comprehensive introduction to LabVIEW FPGA, a package allowing the programming of intelligent digital controllers in field programmable gate arrays (FPGAs) using graphical code. It shows how both potent...
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ISBN:
(数字)9783319266565
ISBN:
(纸本)9783319266558
This book is a comprehensive introduction to LabVIEW FPGA, a package allowing the programming of intelligent digital controllers in field programmable gate arrays (FPGAs) using graphical code. It shows how both potential difficulties with understanding and programming in VHDL and the consequent difficulty and slowness of implementation can be sidestepped. The text includes a clear theoretical explanation of fuzzy logic (type 1 and type 2) with case studies that implement the theory and systematically demonstrate the implementation process. It goes on to describe basic and advanced levels of programming LabVIEW FPGA and show how implementation of fuzzy-logic control in FPGAs improves system responses. A complete toolkit for implementing fuzzy controllers in LabVIEW FPGA has been developed with the book so that readers can generate new fuzzy controllers and deploy them immediately. Problems and their solutions allow readers to practice the techniques and to absorb the theoretical ideas as they arise. Fuzzy logic Type 1 and Type 2 Based on LabVIEW FPGA, helps students studying embedded control systems to design and program those controllers more efficiently and to understand the benefits of using fuzzy logic in doing so. Researchers working with FPGAs find the text useful as an introduction to LabVIEW and as a tool helping them design embedded systems.
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