A note on T\"uring's 1936

T\"uring's argument that there can be no machine computing the diagonal on the enumeration of the computable sequences is not a demonstration.Comment: 4 pages, for more information see http://paolacattabriga.wordpress.com

KED: a deontic theorem prover

Deontic logic (DL) is increasingly recognized as an indispensable tool in such application areas as formal representation of legal knowledge and reasoning, formal specification of computer systems and formal analysis of database integrity constraints. Despite this acknowledgement, there have been few attempts to provide computationally tractable inference mechanisms for DL. In this paper we shall be concerned with providing a computationally oriented proof method for standard DL (SDL), i.e., normal systems of modal logic with the usual possible-worlds semantics. Because of the natural and easily implementable style of proof construction it uses, this method seems particularly well-suited for applications in the AI and Law field, and though in the present version it works for SDL only, it forms an appropriate basis for developing efficient proof methods for more expressive and sophisticated extensions of SDL

A modal computational framework for default reasoning

Usually a default rule A : B/C is intended to mean that if A holds in a state of affairs a B is consistent, then C follows by default. However, C is not a necessary conclusion: different states of affairs are possible (conceivable). According to this view, Meyer and van der Hoek developed a multimodal logic, called S5P(n), for treating non-monotonic reasoning in a monotonic setting. In this paper we shall describe a proof search algorithm for S5P(n) which has been implemented as a Prolog Interpreter

An automated approach to normative reasoning

Deontic logic (DL) is increasingly recognized as an indispensable tool in such application areas as formal representation of legal knowledge and reasoning, formal specification of computer systems and formal analysis of database integrity constraints. Despite this acknowledgement, there have been few attempts to provide computationally tractable inference mechanisms for DL. In this paper we shall be concerned with providing a computationally oriented proof method for standard DL (SDL), i.e., normal systems of modal logic with the usual possible-worlds semantics. Because of the natural and easily implementable style of proof construction it uses, this method seems particularly well-suited for applications in the AI and Law field, and though in the present version it works for SDL only, it forms an appropriate basis for developing efficient proof methods for more expressive and sophisticated extensions of SDL

Complexity computation for compact 3-manifolds via crystallizations and Heegaard diagrams

The idea of computing Matveev complexity by using Heegaard decompositions has been recently developed by two different approaches: the first one for closed 3-manifolds via crystallization theory, yielding the notion of Gem-Matveev complexity; the other one for compact orientable 3-manifolds via generalized Heegaard diagrams, yielding the notion of modified Heegaard complexity. In this paper we extend to the non-orientable case the definition of modified Heegaard complexity and prove that for closed 3-manifolds Gem-Matveev complexity and modified Heegaard complexity coincide. Hence, they turn out to be useful different tools to compute the same upper bound for Matveev complexity.Comment: 12 pages; accepted for publication in Topology and Its Applications, volume containing Proceedings of Prague Toposym 201

NEW EARLY HOLOCENE SETTLEMENT IN CENTRAL ITALY: THE MESOLITHIC SITE OF CONTRADA PACE (MARCHE REGION)

Early Holocene hunter-gatherer settlements are spread throughout Italy and testify to the exploitation of very different landscapes. Nonetheless, their preservation state is not always exceptional. This is not the case for Contrada Pace, an archaeological site recently discovered on a terrace of the Chienti river in central-eastern Italy. This paper reports on the geomorphological, pedo-stratigraphic, and archaeological record of one of the most complete and well-preserved Early Mesolithic open-air sites in Italy and southern Europe. Micro-stratigraphic excavations extended over more than 500 square meters have exposed a buried paleosol with anthropogenic features, which contained thousand lithic artefacts and organic remains framed in the context of a primary forest. These findings appear clustered in different functional areas that yielded multiple structured features. The field evidence integrated by radiocarbon dating and archaeobotanical, archaeomalacological and zooarchaeological data allowed to propose a first interpretation of the general structure of the site and the most significant featuresThe archaeological excavation of the site was carried out by ArcheoLAB (Macerata, Italy) in the framework of construction activities promoted by the Province of Macerata and the Municipality of Tolentino. DV has received funding from the European Union's Horizon 2020 research and innovation programme (Grant Agreement number: 886476 - LiMPH - H2020-MSCA-IF-2019). The archaeobotanical study and 14C dates were funded by the European Research Council (ERC) as part of the Research and Innovation program of the European Community Horizon 2020 (HIDDEN FOODS no.639286 to EC)