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Author Della Penna, Giuseppe; Intrigila, Benedetto; Tronci, Enrico; Venturini Zilli, Marisa
Title Synchronized Regular Expressions Type Journal Article
Year 2002 Publication Electr. Notes Theor. Comput. Sci. Abbreviated Journal
Volume 62 Issue Pages 195-210
Keywords
Abstract Text manipulation is one of the most common tasks for everyone using a computer. The increasing number of textual information in electronic format that every computer user collects everyday stresses the need of more powerful tools to interact with texts. Indeed, much work has been done to provide nonprogramming tools that can be useful for the most common text manipulation issues. Regular Expressions (RE), introduced by Kleene, are well–known in the formal language theory. RE received several extensions, depending on the application of interest. In almost all the implementations of RE search algorithms (e.g. the egrep [A] UNIX command, or the Perl [17] language pattern matching constructs) we find backreferences (as defind in [1]), i.e. expressions that make reference to the string matched by a previous subexpression. Generally speaking, it seems that all the kinds of synchronizations between subexpressions in a RE can be very useful when interacting with texts. Therefore, we introduce the Synchronized Regular Expressions (SRE) as a derivation of the Regular Expressions. We use SRE to present a formal study of the already known backreferences extension, and of a new extension proposed by us, which we call the synchronized exponents. Moreover, since we are talking about formalisms that should have a practical utility and can be used in the real world, we have the problem of how to present SRE to the final users. Therefore, in this paper we also propose a user–friendly syntax for SRE to be used in implementations of SRE–powered search algorithms.
Address
Corporate Author Thesis
Publisher Place of Publication Editor (down)
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes TOSCA 2001, Theory of Concurrency, Higher Order Languages and Types Approved yes
Call Number Sapienza @ mari @ entcs02 Serial 46
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Author Tronci, Enrico; Della Penna, Giuseppe; Intrigila, Benedetto; Venturini Zilli, Marisa
Title A Probabilistic Approach to Automatic Verification of Concurrent Systems Type Conference Article
Year 2001 Publication 8th Asia-Pacific Software Engineering Conference (APSEC) Abbreviated Journal
Volume Issue Pages 317-324
Keywords
Abstract The main barrier to automatic verification of concurrent systems is the huge amount of memory required to complete the verification task (state explosion). In this paper we present a probabilistic algorithm for automatic verification via model checking. Our algorithm trades space with time. In particular, when memory is full because of state explosion our algorithm does not give up verification. Instead it just proceeds at a lower speed and its results will only hold with some arbitrarily small error probability. Our preliminary experimental results show that by using our probabilistic algorithm we can typically save more than 30% of RAM with an average time penalty of about 100% w.r.t. a deterministic state space exploration with enough memory to complete the verification task. This is better than giving up the verification task because of lack of memory.
Address
Corporate Author Thesis
Publisher IEEE Computer Society Place of Publication Macau, China Editor (down)
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0-7695-1408-1 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Sapienza @ mari @ apsec01 Serial 43
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Author Della Penna, Giuseppe; Intrigila, Benedetto; Tronci, Enrico; Venturini Zilli, Marisa
Title Synchronized regular expressions Type Journal Article
Year 2003 Publication Acta Inf. Abbreviated Journal
Volume 39 Issue 1 Pages 31-70
Keywords
Abstract Text manipulation is one of the most common tasks for everyone using a computer. The increasing number of textual information in electronic format that every computer user collects everyday also increases the need of more powerful tools to interact with texts. Indeed, much work has been done to provide simple and versatile tools that can be useful for the most common text manipulation tasks. Regular Expressions (RE), introduced by Kleene, are well known in the formal language theory. RE have been extended in various ways, depending on the application of interest. In almost all the implementations of RE search algorithms (e.g. the egrep [15] UNIX command, or the Perl [20] language pattern matching constructs) we find backreferences, i.e. expressions that make reference to the string matched by a previous subexpression. Generally speaking, it seems that all kinds of synchronizations between subexpressions in a RE can be very useful when interacting with texts. In this paper we introduce the Synchronized Regular Expressions (SRE) as an extension of the Regular Expressions. We use SRE to present a formal study of the already known backreferences extension, and of a new extension proposed by us, which we call the synchronized exponents. Moreover, since we are dealing with formalisms that should have a practical utility and be used in real applications, we have the problem of how to present SRE to the final users. Therefore, in this paper we also propose a user-friendly syntax for SRE to be used in implementations of SRE-powered search algorithms.
Address
Corporate Author Thesis
Publisher Place of Publication Editor (down)
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Sapienza @ mari @ actainf03 Serial 39
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