1,721,224 research outputs found
Il discorso polemico. Controversia, invettiva, 'pamphlet'. Atti del XXXIII Convegno Interuniversitario (Bressanone/Brixen, 7-10 luglio 2005)
No full textIl doppio processo alla volpe nella 'Reynaerts historie' neerlandese
No full textPresentazione e analisi delle principali versioni neerlandesi della volpe Renard. Ci si sofferma in particolare sulla continuazione quattrocentesca (Reynaerts historie) della prima versione duecentesca (Van den vos Reynaerde) e sul senso di quest'operazione di parziale riproposizione ripetitiva della prima versione, indagando il riuso del modello (anche in rapporto alle branches francesi), il quadro storico-culturale e ideologico di riferimento della nuova opera e l'uso delle tecniche retoriche da parte della volpe
"Un oulipien est un rat qui construit le labyrinthe dont il se propose plus tard de sortir, un labyrinthe de mots, de sons, de phrases, de caractères. Forme della ripetizione in Georges Perec
No full text
Parametric Interval Temporal Logic over Infinite Words
Full text linkModel checking for Halpern and Shoham’s interval temporal logic HS has been recently investigated in a systematic way, and it is known to be decidable under three distinct semantics. Here, we focus on the trace-based semantics, where the infinite execution paths (traces) of the given (finite) Kripke structure are the main semantic entities. In this setting, each finite infix of a trace is interpreted as an interval, and a proposition holds over an interval if and only if it holds over each component state (homogeneity assumption). In this paper, we introduce a quantitative extension of HS over traces, called parametric HS (PHS). The novel logic allows to express parametric timing constraints on the duration (length) of the intervals. We show that checking the existence of a parameter valuation for which a Kripke structure satisfies a PHS formula (model checking), or a PHS formula admits a trace as a model under the homogeneity assumption (satisfiability) is decidable. Moreover, we identify a fragment of PHS which subsumes parametric LTL and for which model checking and satisfiability are shown to be EXPSPACE-complete
A Quantitative Extension of Interval Temporal Logic over Infinite Words
Full text linkModel checking (MC) for Halpern and Shoham’s interval temporal logic HS has been recently investigated in a systematic way, and it is known to be decidable under three distinct semantics (state-based, trace-based and tree-based semantics), all of them assuming homogeneity in the propositional valuation. Here, we focus on the trace-based semantics, where the main semantic entities are the infinite execution paths (traces) of the given Kripke structure. We introduce a quantitative extension of HS over traces, called Difference HS (DHS), allowing one to express timing constraints on the difference among interval lengths (durations). We show that MC and satisfiability of full DHS are in general undecidable, so, we investigate the decidability border for these problems by considering natural syntactical fragments of DHS. In particular, we identify a maximal decidable fragment DHSsimple of DHS proving in addition that the considered problems for this fragment are at least 2Expspace-hard. Moreover, by exploiting new results on linear-time hybrid logics, we show that for an equally expressive fragment of DHSsimple, the problems are Expspace-complete. Finally, we provide a characterization of HS over traces by means of the one-variable fragment of a novel hybrid logic
Asynchronous Extensions of HyperLTL
Full text linkHyperproperties are a modern specification paradigm that extends trace properties to express properties of sets of traces. Temporal logics for hyperproperties studied in the literature, including HyperLTL, assume a synchronous semantics and enjoy a decidable model checking problem. In this paper, we introduce two asynchronous and orthogonal extensions of HyperLTL, namely Stuttering HyperLTL (HyperLTLS) and Con HyperLTL (HyperLTLC). Both of these extensions are useful, for instance, to formulate asynchronous variants of information-flow security properties. We show that for these logics, model checking is in general undecidable. On the positive side, for each of them, we identify a fragment with a decidable model checking that subsumes HyperLTL and that can express meaningful asynchronous requirements. Moreover, we provide the exact computational complexity of model checking for these two fragments which, for the HyperLTLS fragment, coincides with that of the strictly less expressive logic HyperLTL
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