On the State Reachability Problem for Concurrent Programs Under Power

2021 ◽  
pp. 47-59
Author(s):  
Parosh Aziz Abdulla ◽  
Mohamed Faouzi Atig ◽  
Ahmed Bouajjani ◽  
Egor Derevenetc ◽  
Carl Leonardsson ◽  
...  
Keyword(s):  
The State ◽  
Concurrent Programs ◽  
Reachability Problem

scholarly journals Reachability Analysis of Asynchronous Dynamic Pushdown Networks Based on Tree Semantics Approach

2018 ◽  
Vol 4 (4) ◽  
pp. 287
Author(s):  
Guodong Wu ◽  
Junyan Qian
Keyword(s):  
Reachability Analysis ◽  
Concurrent Programs ◽  
Abstract Model ◽  
Reachability Problem ◽  
Interleaving Semantics ◽  
Recursive Procedures ◽  
Backward Analysis

<em>ADPN (Asynchronous Dynamic Pushdown Networks) are an abstract model for concurrent programs with recursive procedures and dynamic thread creation. Usually, asynchronous dynamic pushdown networks are described with interleaving semantics, in which the backward analysis is not effective. In order to improve interleaving semantics, tree semantics approach was introduced. This paper extends the tree semantics to ADPN. Because the reachability problem of ADPN is also undecidable, we address the context-bounded reachability problem and provide an algorithm for backward reachability analysis with tree-based semantics Approach.</em>

A CONSTRUCTIVE METHOD FOR FINDING LEGAL TRANSITION SEQUENCES IN PETRI NETS

1998 ◽  
Vol 08 (01) ◽  
pp. 189-222 ◽  
Author(s):  
JENG S. HUANG ◽  
TADAO MURATA
Keyword(s):  
Petri Nets ◽  
Petri Net ◽  
Nonnegative Integer ◽  
State Equation ◽  
The State ◽  
Constructive Method ◽  
Reachability Problem ◽  
Search Effort ◽  
Representation Systems ◽  
Integer Solutions

This paper considers the Petri net reachability problem formulated in terms of nonnegative integer solutions of the state equation and their net representation systems. Our main contributions are twofold. First, we show that algorithms for finding legal transition sequences can be easily given for subclasses of Petri nets where reachability criteria are known or can be formulated by our method. Second, for the general reachability problem where reachability theorems or criteria are not known, and thus an exhaustive search for legal transition sequences is inevitable, we introduce the notion of non-crucial sequences to reduce the search effort.

scholarly journals Dynamic Slicing for Concurrent Constraint Languages

2020 ◽  
Vol 177 (3-4) ◽  
pp. 331-357
Author(s):  
Moreno Falaschi ◽  
Maurizio Gabbrielli ◽  
Carlos Olarte ◽  
Catuscia Palamidessi
Keyword(s):  
Constraint Programming ◽  
Spatial Information ◽  
Linear Logic ◽  
The State ◽  
Concurrent Programs ◽  
Redundant Information ◽  
Dynamic Slicing ◽  
Concurrent Constraint Programming ◽  
Constraint Languages

Concurrent Constraint Programming (CCP) is a declarative model for concurrency where agents interact by telling and asking constraints (pieces of information) in a shared store. Some previous works have developed (approximated) declarative debuggers for CCP languages. However, the task of debugging concurrent programs remains difficult. In this paper we define a dynamic slicer for CCP (and other language variants) and we show it to be a useful companion tool for the existing debugging techniques. We start with a partial computation (a trace) that shows the presence of bugs. Often, the quantity of information in such a trace is overwhelming, and the user gets easily lost, since she cannot focus on the sources of the bugs. Our slicer allows for marking part of the state of the computation and assists the user to eliminate most of the redundant information in order to highlight the errors. We show that this technique can be tailored to several variants of CCP, such as the timed language ntcc, linear CCP (an extension of CCPbased on linear logic where constraints can be consumed) and some extensions of CCP dealing with epistemic and spatial information. We also develop a prototypical implementation freely available for making experiments.

Practical Picture Processing

1974 ◽  
Vol 32 ◽  
pp. 338-339
Author(s):  
T. A. Welton
Keyword(s):  
Radiation Damage ◽  
Coherence Length ◽  
Spatial Information ◽  
State Of The Art ◽  
Coherent Radiation ◽  
The State ◽  
Energy Spread ◽  
Electron Micrograph ◽  
Picture Processing ◽  
Molecular Skeleton

Various authors have emphasized the spatial information resident in an electron micrograph taken with adequately coherent radiation. In view of the completion of at least one such instrument, this opportunity is taken to summarize the state of the art of processing such micrographs. We use the usual symbols for the aberration coefficients, and supplement these with £ and 6 for the transverse coherence length and the fractional energy spread respectively. He also assume a weak, biologically interesting sample, with principal interest lying in the molecular skeleton remaining after obvious hydrogen loss and other radiation damage has occurred.

Pragmatic versus Morphological/Syntactic Criteria for Language Referrals

1980 ◽  
Vol 11 (2) ◽  
pp. 85-94 ◽  
Author(s):  
Jack Damico ◽  
John W. Oller
Keyword(s):  
Grade Level ◽  
The State ◽  
Verb Agreement ◽  
Remedial Programs ◽  
Service Training ◽  
Traditional Approaches ◽  
Communicative Effectiveness

Two methods of identifying language disordered children are examined. Traditional approaches require attention to relatively superficial morphological and surface syntactic criteria, such as, noun-verb agreement, tense marking, pluralization. More recently, however, language testers and others have turned to pragmatic criteria focussing on deeper aspects of meaning and communicative effectiveness, such as, general fluency, topic maintenance, specificity of referring terms. In this study, 54 regular K-5 teachers in two Albuquerque schools serving 1212 children were assigned on a roughly matched basis to one of two groups. Group S received in-service training using traditional surface criteria for referrals, while Group P received similar in-service training with pragmatic criteria. All referrals from both groups were reevaluated by a panel of judges following the state determined procedures for assignment to remedial programs. Teachers who were taught to use pragmatic criteria in identifying language disordered children identified significantly more children and were more often correct in their identification than teachers taught to use syntactic criteria. Both groups identified significantly fewer children as the grade level increased.

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