149 research outputs found

    Automated Reasoning and Presentation Support for Formalizing Mathematics in Mizar

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    This paper presents a combination of several automated reasoning and proof presentation tools with the Mizar system for formalization of mathematics. The combination forms an online service called MizAR, similar to the SystemOnTPTP service for first-order automated reasoning. The main differences to SystemOnTPTP are the use of the Mizar language that is oriented towards human mathematicians (rather than the pure first-order logic used in SystemOnTPTP), and setting the service in the context of the large Mizar Mathematical Library of previous theorems,definitions, and proofs (rather than the isolated problems that are solved in SystemOnTPTP). These differences poses new challenges and new opportunities for automated reasoning and for proof presentation tools. This paper describes the overall structure of MizAR, and presents the automated reasoning systems and proof presentation tools that are combined to make MizAR a useful mathematical service.Comment: To appear in 10th International Conference on. Artificial Intelligence and Symbolic Computation AISC 201

    New results on rewrite-based satisfiability procedures

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    Program analysis and verification require decision procedures to reason on theories of data structures. Many problems can be reduced to the satisfiability of sets of ground literals in theory T. If a sound and complete inference system for first-order logic is guaranteed to terminate on T-satisfiability problems, any theorem-proving strategy with that system and a fair search plan is a T-satisfiability procedure. We prove termination of a rewrite-based first-order engine on the theories of records, integer offsets, integer offsets modulo and lists. We give a modularity theorem stating sufficient conditions for termination on a combinations of theories, given termination on each. The above theories, as well as others, satisfy these conditions. We introduce several sets of benchmarks on these theories and their combinations, including both parametric synthetic benchmarks to test scalability, and real-world problems to test performances on huge sets of literals. We compare the rewrite-based theorem prover E with the validity checkers CVC and CVC Lite. Contrary to the folklore that a general-purpose prover cannot compete with reasoners with built-in theories, the experiments are overall favorable to the theorem prover, showing that not only the rewriting approach is elegant and conceptually simple, but has important practical implications.Comment: To appear in the ACM Transactions on Computational Logic, 49 page

    Pathways to care in youth and young adults at clinical high risk for psychosis in Switzerland: Current situation and clinical implementation of the PsyYoung project

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    Aim We aim to give an insight into the current situation in Switzerland concerning the pathways to care of young people with clinical high risk of psychosis. In a second step we propose a procedure of optimizing pathways to care developed within the project PsyYoung. Methods A qualitative survey derived and adapted from Kotlicka-Antczak et al. (2020) was conducted in large early detection services of three Swiss cantons (Geneva, Basel-Stadt, Vaud) focusing on pathways to care. More specifically, using questionnaires delivered to the heads of participating services, information was collected on referral sources, on activities to implement outreach campaigns and on the use of a pre-screening tool. Results Main results on referral source indicated that sources were variable but seemed to come primarily from the medical sector and more so from the psychiatric sector. Very few referrals came from non-medical sectors. Outreach activities included the contact to other clinics as well as through brochures and posters. All services but one used the Prodromal Questionnaire – 16 as pre-screening tool. Conclusions All in all, the results indicate a referral and care pathway system implemented mostly within the medical and particularly mental health sector. Accordingly, the PsyYoung project proposes a procedure for pathways to care which could help overcome the obstacle of referrals being restrained to a narrow field of mental health and to harmonize the referral process within services dedicated to the same aim of helping young people at high risk of developing a psychosis.We would like to acknowledge Promotion Santé Suisse (grant number 19.313) and the Office Fédéral de la Santé Publique for granting and sustaining this project. Dr Luis Alameda thanks the Foundation Adrian and Simone Frutiger and Carigest SA Foundation for their support. Open access funding provided by Universite de Lausanne.Peer reviewe

    BSP Functional Programming: Examples of a Cost Based Methodology

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    Abstract. Bulk-Synchronous Parallel ML (BSML) is a functional data-parallel language for the implementation of Bulk-Synchronous Parallel (BSP) algorithms. It makes an estimation of the execution time (cost) possible. This paper presents some general examples of BSML programs and a comparison of their predicted costs with the measured execution time on a parallel machine

    Perioperative thirst: an analysis from the perspective of the Symptom Management Theory

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    A theoretical study aimed to analyze the existing knowledge in the literature on the perioperative thirst symptom from the perspective of Symptom Management Theory, and supplemented with the experience of the study group and thirst research. Thirst is described as a very intense symptom occurring in the perioperative period, and for this reason it cannot be ignored. The Symptom Management Theory is adequate for understanding the thirst symptom and is a deductive theory, focused on the domains of the Person, Environment and Health / Illness Status, as well as on the dimensions of Experience, Management Strategies and Symptom Outcomes. Using the theory leads us to consider perioperative thirst in its multifactorial aspects, analyzing the interrelation of its domains and dimensions in order to draw attention to this symptom that has been insufficiently valued, recorded and treated in clinical practice

    Quaternary glacial history of the Mediterranean mountains

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    Glacial and periglacial landforms are widespread in the mountains of the Mediterranean region. The evidence for glacial and periglacial activity has been studied for over 120 years and it is possible to identify three phases of development in this area of research. First, a pioneer phase characterized by initial descriptive observations of glacial landforms; second, a mapping phase whereby the detailed distribution of glacial landforms and sediments have been depicted on geomorphological maps; and, third, an advanced phase characterized by detailed understanding of the geochronology of glacial sequences using radiometric dating alongside detailed sedimentological and stratigraphical analyses. It is only relatively recently that studies of glaciated mountain terrains in the Mediterranean region have reached an advanced phase and it is now clear from radiometric dating programmes that the Mediterranean mountains have been glaciated during multiple glacial cycles. The most extensive phases of glaciation appear to have occurred during the Middle Pleistocene. This represents a major shift from earlier work whereby many glacial sequences were assumed to have formed during the last cold stage. Glacial and periglacial deposits from multiple Quaternary cold stages constitute a valuable palaeoclimatic record. This is especially so in the Mediterranean mountains, since mountain glaciers in this latitudinal zone would have been particularly sensitive to changes in the global climate system. © 2006 Edward Arnold (Publishers) Ltd
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