The proceedings contain 26 papers. The special focus in this conference is on Application and theory of Petri Nets. The topics include: Performance issues in parallel programming;combining petri nets and other formal ...
ISBN:
(纸本)9783540556763
The proceedings contain 26 papers. The special focus in this conference is on Application and theory of Petri Nets. The topics include: Performance issues in parallel programming;combining petri nets and other formal methods;place bisimulations in petri nets;a polynomial-time graph algorithm to decide liveness of some basic classes of bounded petri nets;refinement and simulation of nets - a categorical characterisation;scheduling hard real time systems using high-level petri nets;towards a modular analysis of coloured petri nets;a proof of the rank theorem for extended free choice nets;on the product form solution for stochastic petri nets;obtaining deadlock-preserving skeletons for coloured nets;formal verification of an arbiter cascade;constructs for modeling information systems with petri nets;construction of a class of safe petri nets by presenting firing sequences;an efficient polynomial-time algorithm to decide liveness and boundedness of free-choice nets;hierarchical solution of generalized stochastic petri nets by means of traffic processes;concurrency relations and the safety problem for petri nets;high-level nets and linear logic;liveness and boundedness analysis for petri nets with event graph modules;on weighted T-systems;using petri nets to develop programs for PLC systems;modelling and control of complex logistic systems for manufacturing;analysis of an ada system using coloured petri nets and occurrence graphs;the stubborn set method in practice and modeling fine grain computation via the fusion of two extended petri nets.
logicprogramming systems which use parallel strategies for computing "and" and "or" are theoretically elegant, but systems which use sequential strategies are far more widely used and do not fit w...
logicprogramming systems which use parallel strategies for computing "and" and "or" are theoretically elegant, but systems which use sequential strategies are far more widely used and do not fit well into the traditional theory of logicprogramming. This thesis presents operational and proof-theoretic characterisa- tions for systems having each of the possible combinations of parallel or sequential "and" and parallel or sequential "or". The operational semantics are in the form of an abstract machine. The four control strategies emerge as simple variants of this machine with varying degrees of determinism; some of these variants have equivalent, compositional operational semantics, which are given. The proof-theoretic characterisations consist of a single central sequent calcu- lus, LKE (similar to Gentzen's sequent calculus for classical first order logic), and sets of axioms which capture the success or failure of queries in the four control strategies in a highly compositional, logical way. These proof-theoretic character- isations can be seen as logical semantics of the logicprogramming languages. The proof systems can also be used in practice to prove more general properties of logic programs, although it is shown that they are unavoidably incomplete for this purpose. One aspect of this incompleteness is that it is not possible to derive all valid sequents having free variables; however, induction rules are given which can help to prove many useful sequents of this kind.
Past attempts to apply Girard's linear logic have either had a clear relation to the theory (Lafont, Holmstrom, Abramsky) or a clear pratical value (Guzman and Hudak, Wadler), but not both. This paper defines a se...
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ISBN:
(纸本)9780897914338
Past attempts to apply Girard's linear logic have either had a clear relation to the theory (Lafont, Holmstrom, Abramsky) or a clear pratical value (Guzman and Hudak, Wadler), but not both. This paper defines a sequence of languages based on linear logic that span the gap between theory and practice. Type reconstruction in a linear type system can derive information about sharing. An approach to linear type reconstruction based on use types is presented. Applications to the array update problem are considered.
Guarded Functional programming is an approach to integrate functional programming, represented by equations and rewriting, and logicprogramming, represented by Horn clauses and SLD-resolution: the selection of a guar...
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logicprogramming and (Hyper-)Graph Rewriting are two well known fields of Computer Science. In this paper we show how to model logic program computations through algebraic techniques familiar to the graph rewriting c...
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This paper proposes a type system for logicprogramming where types are structured in two ways. Firstly, functions and predicates may be declared with types containing type parameters which are universally quantified ...
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The proceedings contain 24 papers. The special focus in this conference is on theory and practice of Software Development. The topics include: Full abstraction for series-parallel pomsets;on causality observed increme...
ISBN:
(纸本)9783540539827
The proceedings contain 24 papers. The special focus in this conference is on theory and practice of Software Development. The topics include: Full abstraction for series-parallel pomsets;on causality observed incrementally, finally;on the domain of traces and sequential composition;compilation of pattern matching with associative-commutative functions;algebraic graph rewriting using a single pushout;unifying initial and loose semantics of parameterized specifications in an arbitrary institution;program specification and data refinement in type theory;smile analysis of linear congruence equalities among variables of a program;simple solutions for approximate tree matching problems;the tree inclusion problem;introducing a calculus of trees;domains in a realizabifity framework;iteration algebras;logicprogramming as hypergraph rewriting;a fuuy abstract model for concurrent constraint programming;a solved form algorithm for ask and tell herbrand constraints;a calculus of broadcasting systems;on the complexity of equation solving in process algebra;comparative semantics for a real-time programming language with integration;a complete proof system for timed observations and type inference with inequalities.
The proceedings contain 27 papers. The special focus in this conference is on theory and practice of Software Development. The topics include: CCS for OO and LP;an extended expansion theorem;concurrent abstract machin...
ISBN:
(纸本)9783540539810
The proceedings contain 27 papers. The special focus in this conference is on theory and practice of Software Development. The topics include: CCS for OO and LP;an extended expansion theorem;concurrent abstract machines (abstract);knowledge and probability in distributed systems (abstract);verification methods for finite systems (abstract);interactive interworking for interoperating systems (abstract);formal specification of object systems;on the relationship between algebraic module specifications and program modules;construction and reuse of formal program developments;a theory of program modifications;proving termination of logic programs by exploiting term properties;parametric order-sorted types in logicprogramming;exploiting non-determinism through laziness in guarded functional latlguages;non-standard interpretations of LOTOS specifications;a new technique for stricmess analysis;using higher order logic for modelling real-time protocols;combining interaction and automation in process algebra verification;refining interfaces of communicating systems;actor-oriented system specification with dynamic logic;towards a formally based component description language;on addition schemes;efficient code motion and an adaption to strength reduction;on narrowing strategies for partial non-strict functions and from reduction machines to narrowing machines.
Recent results [5] have shown that concurrent logicprogramming has a very simple model, based on linear sequences, which is fully abstract with respect to the parallel operator and finite observables. This is intrins...
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We consider a language for reasoning about probability which allows us to make statements such as “the probability of E1 is less than 13” and “the probability of E1 is at least twice the probability of E2,” where ...
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We consider a language for reasoning about probability which allows us to make statements such as “the probability of E1 is less than 13” and “the probability of E1 is at least twice the probability of E2,” where E1 and E2 are arbitrary events. We consider the case where all events are measurable (i.e., represent measurable sets) and the more general case, which is also of interest in practice, where they may not be measurable. The measurable case is essentially a formalization of (the propositional fragment of) Nilsson"s probabilistic logic. As we show elsewhere, the general (nonmeasurable) case corresponds precisely to replacing probability measures by Dempster-Shafer belief functions. In both cases, we provide a complete axiomatization and show that the problem of deciding satisfiability is NP-complete, no worse than that of propositional logic. As a tool for proving our complete axiomatizations, we give a complete axiomatization for reasoning about Boolean combinations of linear inequalities, which is of independent interest. This proof and others make crucial use of results from the theory of linear programming. We then extend the language to allow reasoning about conditional probability and show that the resulting logic is decidable and completely axiomatizable, by making use of the theory of real closed fields.
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