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Author Intrigila, Benedetto; Salvo, Ivano; Sorgi, Stefano
Title A characterization of weakly Church-Rosser abstract reduction systems that are not Church-Rosser Type Journal Article
Year 2001 Publication Information and Computation Abbreviated Journal
Volume 171 Issue 2 Pages 137-155
Keywords
Abstract Basic properties of rewriting systems can be stated in the framework of abstract reduction systems (ARS). Properties like confluence (or Church-Rosser, CR) and weak confluence (or weak Church-Rosser, WCR) and their relationships can be studied in this setting: as a matter of fact, well-known counterexamples to the implication WCR CR have been formulated as ARS. In this paper, starting from the observation that such counterexamples are structurally similar, we set out a graph-theoretic characterization of WCR ARS that is not CR in terms of a suitable class of reduction graphs, such that in every WCR not CR ARS, we can embed at least one element of this class. Moreover, we give a tighter characterization for a restricted class of ARS enjoying a suitable regularity condition. Finally, as a consequence of our approach, we prove some interesting results about ARS using the mathematical tools developed. In particular, we prove an extension of the Newman’s lemma and we find out conditions that, once assumed together with WCR property, ensure the unique normal form property. The Appendix treats two interesting examples, both generated by graph-rewriting rules, with specific combinatorial properties.
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Corporate Author Thesis
Publisher Academic Press, Inc. Place of Publication Duluth, MN, USA Editor (up)
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0890-5401 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Sapienza @ mari @ Intrigila-Salvo-Sorgi:01 Serial 68
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Author Bucciarelli, Antonio; Piperno, Adolfo; Salvo, Ivano
Title Intersection types and λ-definability Type Journal Article
Year 2003 Publication Mathematical Structures in Computer Science Abbreviated Journal
Volume 13 Issue 1 Pages 15-53
Keywords
Abstract This paper presents a novel method for comparing computational properties of λ-terms that are typeable with intersection types, with respect to terms that are typeable with Curry types. We introduce a translation from intersection typing derivations to Curry typeable terms that is preserved by β-reduction: this allows the simulation of a computation starting from a term typeable in the intersection discipline by means of a computation starting from a simply typeable term. Our approach proves strong normalisation for the intersection system naturally by means of purely syntactical techniques. The paper extends the results presented in Bucciarelli et al. (1999) to the whole intersection type system of Barendregt, Coppo and Dezani, thus providing a complete proof of the conjecture, proposed in Leivant (1990), that all functions uniformly definable using intersection types are already definable using Curry types.
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Corporate Author Thesis
Publisher Cambridge University Press Place of Publication New York, NY, USA Editor (up)
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0960-1295 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Sapienza @ mari @ Bucciarelli-Piperno-Salvo:MSCS-03 Serial 69
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Author Bucciarelli, Antonio; Salvo, Ivano
Title Totality, Definability and Boolean Circuits Type Journal Article
Year 1998 Publication Abbreviated Journal
Volume 1443 Issue Pages 808-819
Keywords
Abstract In the type frame originating from the flat domain of boolean values, we single out elements which are hereditarily total. We show that these elements can be defined, up to total equivalence, by sequential programs. The elements of an equivalence class of the totality equivalence relation (totality class) can be seen as different algorithms for computing a given set-theoretic boolean function. We show that the bottom element of a totality class, which is sequential, corresponds to the most eager algorithm, and the top to the laziest one. Finally we suggest a link between size of totality classes and a well known measure of complexity of boolean functions, namely their sensitivity.
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Corporate Author Thesis
Publisher Springer Place of Publication Editor (up)
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 @ bucciarelli-salvo:98 Serial 70
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Author Bucciarelli, Antonio; de Lorenzis, Silvia; Piperno, Adolfo; Salvo, Ivano
Title Some Computational Properties of Intersection Types (Extended Abstract) Type Journal Article
Year 1999 Publication Abbreviated Journal
Volume Issue Pages 109-118
Keywords lambda calculusCurry types, intersection types, lambda-definability, lambda-terms, strong normalization
Abstract This paper presents a new method for comparing computation-properties of λ-terms typeable with intersection types with respect to terms typeable with Curry types. In particular, strong normalization and λ-definability are investigated. A translation is introduced from intersection typing derivations to Curry typeable terms; the main feature of the proposed technique is that the translation is preserved by β-reduction. This allows to simulate a computation starting from a term typeable in the intersection discipline by means of a computation starting from a simply typeable term. Our approach naturally leads to prove strong normalization in the intersection system by means of purely syntactical techniques. In addition, the presented method enables us to give a proof of a conjecture proposed by Leivant in 1990, namely that all functions uniformly definable using intersection types are already definable using Curry types.
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Corporate Author Thesis
Publisher IEEE Computer Society Place of Publication Editor (up)
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 @ bucciarelli-delorenzis-piperno-salvo:99 Serial 71
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Author Bono, V.; Salvo, I.
Title A CuCh Interpretation of an Object-Oriented Language Type Journal Article
Year 2001 Publication Electronic Notes in Theoretical Computer Science Abbreviated Journal
Volume 50 Issue 2 Pages 159-177
Keywords
Abstract CuCh machine extends pure lambda–calculus with algebraic data types and provides a the possibility of defining functions over the disjoint sum of algebras. We exploit such natural form of overloading to define a functional interpretation of a simple, but significant fragment of a typical object-oriented language.
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Publisher Elsevier Place of Publication Editor (up)
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes BOTH 2001, Bohm’s theorem: applications to Computer Science Theory (Satellite Workshop of ICALP 2001) Approved yes
Call Number Sapienza @ mari @ Bono-Salvo:BOTH01 Serial 72
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Author Barbanera, Franco; Dezani-Ciancaglini, Mariangiola; Salvo, Ivano; Sassone, Vladimiro
Title A Type Inference Algorithm for Secure Ambients Type Journal Article
Year 2002 Publication Electronic Notes in Theoretical Computer Science Abbreviated Journal
Volume 62 Issue Pages 83-101
Keywords
Abstract We consider a type discipline for the Ambient Calculus that associates ambients with security levels and constrains them to be traversed by or opened in ambients of higher security clearance only. We present a bottom-up algorithm that, given an untyped process P, computes a minimal set of constraints on security levels such that all actions during runs of P are performed without violating the security level priorities. Such an algorithm appears to be a prerequisite to use type systems to ensure security properties in the web scenario.
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Corporate Author Thesis
Publisher Elsevier Place of Publication Editor (up)
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 @ Barbanera-Dezani-Salvo-Sassone:01 Serial 73
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Author Coppo, Mario; Dezani-Ciancaglini, Mariangiola; Giovannetti, Elio; Salvo, Ivano
Title Mobility Types for Mobile Processes in Mobile Ambients Type Journal Article
Year 2003 Publication Electr. Notes Theor. Comput. Sci. Abbreviated Journal
Volume 78 Issue Pages
Keywords
Abstract We present an ambient-like calculus in which the open capability is dropped, and a new form of “lightweightÃ¢â‚¬Âť process mobility is introduced. The calculus comes equipped with a type system that allows the kind of values exchanged in communications and the access and mobility properties of processes to be controlled. A type inference procedure determines the “minimalÃ¢â‚¬Âť requirements to accept a system or a component as well typed. This gives a kind of principal typing. As an expressiveness test, we show that some well known calculi of concurrency and mobility can be encoded in our calculus in a natural way.
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Publisher Place of Publication Editor (up)
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 @ Coppo-Dezani-Giovannetti-Salvo:03 Serial 74
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Author Della Penna, Giuseppe; Intrigila, Benedetto; Melatti, Igor; Tronci, Enrico; Venturini Zilli, Marisa
Title Finite horizon analysis of Markov Chains with the Mur$\varphi$ verifier Type Journal Article
Year 2006 Publication Int. J. Softw. Tools Technol. Transf. Abbreviated Journal
Volume 8 Issue 4 Pages 397-409
Keywords
Abstract In this paper we present an explicit disk-based verification algorithm for Probabilistic Systems defining discrete time/finite state Markov Chains. Given a Markov Chain and an integer k (horizon), our algorithm checks whether the probability of reaching an error state in at most k steps is below a given threshold. We present an implementation of our algorithm within a suitable extension of the Mur$\varphi$ verifier. We call the resulting probabilistic model checker FHP-Mur$\varphi$ (Finite Horizon Probabilistic Mur$\varphi$). We present experimental results comparing FHP-Mur$\varphi$ with (a finite horizon subset of) PRISM, a state-of-the-art symbolic model checker for Markov Chains. Our experimental results show that FHP-Mur$\varphi$ can handle systems that are out of reach for PRISM, namely those involving arithmetic operations on the state variables (e.g. hybrid systems).
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Corporate Author Thesis
Publisher Springer-Verlag Place of Publication Berlin, Heidelberg Editor (up)
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1433-2779 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Sapienza @ mari @ Dimtz06 Serial 78
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Author Della Penna, Giuseppe; Intrigila, Benedetto; Melatti, Igor; Tronci, Enrico; Venturini Zilli, Marisa
Title Exploiting Transition Locality in Automatic Verification of Finite State Concurrent Systems Type Journal Article
Year 2004 Publication Sttt Abbreviated Journal
Volume 6 Issue 4 Pages 320-341
Keywords
Abstract In this paper we show that statistical properties of the transition graph of a system to be verified can be exploited to improve memory or time performances of verification algorithms. We show experimentally that protocols exhibit transition locality. That is, with respect to levels of a breadth-first state space exploration, state transitions tend to be between states belonging to close levels of the transition graph. We support our claim by measuring transition locality for the set of protocols included in the Mur$\varphi$ verifier distribution. We present a cache-based verification algorithm that exploits transition locality to decrease memory usage and a disk-based verification algorithm that exploits transition locality to decrease disk read accesses, thus reducing the time overhead due to disk usage. Both algorithms have been implemented within the Mur$\varphi$ verifier. Our experimental results show that our cache-based algorithm can typically save more than 40% of memory with an average time penalty of about 50% when using (Mur$\varphi$) bit compression and 100% when using bit compression and hash compaction, whereas our disk-based verification algorithm is typically more than ten times faster than a previously proposed disk-based verification algorithm and, even when using 10% of the memory needed to complete verification, it is only between 40 and 530% (300% on average) slower than (RAM) Mur$\varphi$ with enough memory to complete the verification task at hand. Using just 300 MB of memory our disk-based Mur$\varphi$ was able to complete verification of a protocol with about $10^9$ reachable states. This would require more than 5 GB of memory using standard Mur$\varphi$.
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Corporate Author Thesis
Publisher Place of Publication Editor (up)
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 @ DIMTZ04j Serial 91
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Author Della Penna, Giuseppe; Tofani, Alberto; Pecorari, Marcello; Raparelli, Orazio; Intrigila, Benedetto; Melatti, Igor; Tronci, Enrico
Title A Case Study on Automated Generation of Integration Tests Type Conference Article
Year 2006 Publication Fdl Abbreviated Journal
Volume Issue Pages 278-284
Keywords
Abstract
Address
Corporate Author Thesis
Publisher Ecsi Place of Publication Editor (up)
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 978-3-00-019710-9 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Sapienza @ mari @ Dtprimt06 Serial 27
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