425 research outputs found

    Relational semantics of linear logic and higher-order model-checking

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    In this article, we develop a new and somewhat unexpected connection between higher-order model-checking and linear logic. Our starting point is the observation that once embedded in the relational semantics of linear logic, the Church encoding of any higher-order recursion scheme (HORS) comes together with a dual Church encoding of an alternating tree automata (ATA) of the same signature. Moreover, the interaction between the relational interpretations of the HORS and of the ATA identifies the set of accepting states of the tree automaton against the infinite tree generated by the recursion scheme. We show how to extend this result to alternating parity automata (APT) by introducing a parametric version of the exponential modality of linear logic, capturing the formal properties of colors (or priorities) in higher-order model-checking. We show in particular how to reunderstand in this way the type-theoretic approach to higher-order model-checking developed by Kobayashi and Ong. We briefly explain in the end of the paper how his analysis driven by linear logic results in a new and purely semantic proof of decidability of the formulas of the monadic second-order logic for higher-order recursion schemes.Comment: 24 pages. Submitte

    Collusions Between Patients and Clinicians in End-of-Life Care: Why Clarity Matters.

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    Collusion, an unconscious dynamic between patients and clinicians, may provoke strong emotions, unreflected behaviors, and a negative impact on care. Collusions, prevalent in the health care setting, are triggered by situations which signify an unresolved psychological issue relevant for both, patient and clinician. After an introductory definition of collusion, two archetypal situations of collusion-based on material from a regular supervision of a palliative care specialist by a liaison psychiatrist-and means of working through collusion are presented. The theoretical framework of collusion is then described and the conceptual shortcomings of the palliative care literature in this respect discussed, justifying the call for more clarity. Finally, cultural aspects and societal injunctions on the dying, contributing to the development of collusion in end-of-life care, are discussed

    The Effects of Cellulase on Cell Wall Structure and the Rumen Digestion of Alfalfa Silage

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    First- and second-cut alfalfa (Medicago sativa) was ensiled with no additive, microbial (Lactobacillus casei) inoculant, cellulase derived from Acremonium celluloytics Y-94, co-addition of inoculant and cellulase, and formic acid. The resultant silages were digested in the rumen of a dairy cow. The alfalfa and the silages were then examined with scanning electron microscope (SEM) and their chemical characteristics analyzed to evaluate the effects of cellulase on the quality of alfalfa silage and its cell wall structure. The addition of cellulase lend to both a greater loss of parenchymal tissue and decrease in digestibility during rumen degradation than did the other additives moreover, photos taken during SEM examination also showed that cellulase affected cell wall decomposition. The results of this study may suggest that the addition of cellulase affects fiber digestion by ruminant animals

    The Effect of Cellulase on Cell Wall Structure and the Rumen Digestion of Timothy Silage

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    The objective of this study was to determine the effect of additives on the structure changes of related tissues during the ensiling process and the rumen digestion of timothy. In the first cut-timothy, the addition of LC+AC improved the fermentation qualities of the silage. Addition of cellulase resulted in significant decreases in NDF, ADF, cellulose, and hemicellulose content. SEM examination of the samples suggests that the degradation of parenchymal tissues was enhanced by the cellulase, but no significant differences were observed among the additives in the rumen digestion. The NDF and cellulose digestibility of the AC- and LC+AC-treated silages were lower than those of the other silages. In the second one, after digestion in the rumen, there was a marked loss of inner parenchymal tissues in AC and LC+AC-treated silages

    An Elementary Affine λ-Calculus with Multithreading and Side Effects

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    International audienceLinear logic provides a framework to control the complexity of higher-order functional programs. We present an extension of this framework to programs with multithreading and side effects focusing on the case of elementary time. Our main contributions are as follows. First, we introduce a modal call-by-value λ-calculus with multithreading and side effects. Second, we provide a combinatorial proof of termination in elementary time for the language. Third, we introduce an elementary affine type system that guarantees the standard subject reduction and progress properties. Finally, we illustrate the programming of iterative functions with side effects in the presented formalism

    Proof Theory and Ordered Groups

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    Ordering theorems, characterizing when partial orders of a group extend to total orders, are used to generate hypersequent calculi for varieties of lattice-ordered groups (l-groups). These calculi are then used to provide new proofs of theorems arising in the theory of ordered groups. More precisely: an analytic calculus for abelian l-groups is generated using an ordering theorem for abelian groups; a calculus is generated for l-groups and new decidability proofs are obtained for the equational theory of this variety and extending finite subsets of free groups to right orders; and a calculus for representable l-groups is generated and a new proof is obtained that free groups are orderable

    Generic Modal Cut Elimination Applied to Conditional Logics

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    We develop a general criterion for cut elimination in sequent calculi for propositional modal logics, which rests on absorption of cut, contraction, weakening and inversion by the purely modal part of the rule system. Our criterion applies also to a wide variety of logics outside the realm of normal modal logic. We give extensive example instantiations of our framework to various conditional logics. For these, we obtain fully internalised calculi which are substantially simpler than those known in the literature, along with leaner proofs of cut elimination and complexity. In one case, conditional logic with modus ponens and conditional excluded middle, cut elimination and complexity were explicitly stated as open in the literature

    Non-deterministic Boolean Proof Nets

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    16 pagesInternational audienceWe introduce Non-deterministic Boolean proof nets to study the correspondence with Boolean circuits, a parallel model of computation. We extend the cut elimination of Non-deterministic Multiplicative Linear logic to a parallel procedure in proof nets. With the restriction of proof nets to Boolean types, we prove that the cut-elimination procedure corresponds to Non-deterministic Boolean circuit evaluation and reciprocally. We obtain implicit characterization of the complexity classes NP and NC (the efficiently parallelizable functions)
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