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This article has two purposes. The first is to present a final coalgebra construction for finitary endofunctors on Set that uses a certain subset L* of the limit L of the first ω terms in the final sequence. L* is the set of points in L which arise from all coalgebras using their canonical morphisms into L, and it was used earlier for different purposes in Kurz and Pattinson (2005, Mathematical Structures in Computer Science, 15, 543–473). Viglizzo (2005, PhD Dessertation, Indiana University) showed that the same set L* carried a final coalgebra structure for functors in a certain inductively defined family. Our first goal is to generalize this to all finitary endofunctors; the result is implicit in Worrell (2005, Theoritical Computer Science, 338, 184–199). The second goal is to use the final coalgebra construction to propose coalgebraic logics similar to those in Lawrence S. Moss (1999, Annals of Pure and Applied Logic, 96, 277–317) but for all finitary endofunctors F on Set. This time one can dispense with all conditions on F, construct a logical language ℒF directly from it, and prove that two points in a coalgebra satisfy the same sentences of ℒF iff they are identified by the final coalgebra morphism. The language ℒF is very spare, having no boolean connectives. This work on ℒF is thus a re-working of coalgebraic logic for finitary functors on sets. [ABSTRACT FROM PUBLISHER]

This article provides sound and complete logical systems for several fragments of English which go beyond syllogistic logic in that they use verbs as well as other limited syntactic material: universally and existentially quantified noun phrases, building on the work of Nishihara, Morita and Iwata (1990, Systems and Computers in Japan, 21, 96–111); complemented noun phrases, following our Moss (2007, Syllogistic Logic with Complements); and noun phrases which might contain relative clauses, recursively, based on McAllester and Givan (1992, Artifical Intelligence, 56, 1–20). The logics are all syllogistic in the sense that they do not make use of individual variables. Variables in our systems range over nouns, and in the last system, over verbs as well. [ABSTRACT FROM PUBLISHER]

We consider foundational questions related to the definition of functions by corecursion. This method is especially suited to functions into the greatest fixed point of some monotone operator, and it is most applicable in the context of non-wellfounded sets. We review the work on the Special Final Coalgebra Theorem of Aczel [1] and the Corecursion Theorem of Barwise and Moss [4]. We offer a condition weaker than Aczel's condition of uniformity on maps, and then we prove a result relating the operators satisfying the new condition to the smooth operators of [4]. [ABSTRACT FROM PUBLISHER]

This article is intended to provide evidence that the phenomenon of Platonic deception has played a curious and distinctive role in shaping thought about the administration of social order. According to the reading of Plato's Republic, deception is what is needed if the personal interests and motivations of citizens are to be aligned in ways that allow a region to escape ordinary subsistence and enjoy luxurious consumption opportunities instead. According to the Platonic conception of the importance of deception in promoting social organization, the answer to both these questions is a resounding no. Plato did not offer the old adage about ignorance being bliss because, as have been seen, those few in authority are not ignorant at all about what is going on. Rather, the ignorance is confined to the rank-and-file citizenry. The less individuals know about the debauched sources of their prosperity, the more likely that prosperity will endure. Debunkers of the fully-informed-citizen myth do put their ideas in writing and publish their arguments.

This paper studies presentations of the Sierpinski gasket as a final coalgebra for a functor on three categories of metric spaces with additional designated points. The three categories which we study differ on their morphisms: one uses short (non-expanding) maps, the second uses continuous maps, and the third uses Lipschitz maps. The functor in all cases is very similar to what we find in the standard presentation of the gasket as an attractor. It was previously known that the Sierpinski gasket is bilipschitz equivalent (though not isomorhpic) to the final coalgebra of this functor in the category with short maps, and that final coalgebra is obtained by taking the completion of the initial algebra. In this paper, we prove that the Sierpiniski gasket itself is the final coalgebra in the category with continuous maps, though it does not occur as the completion of the initial algebra. In the Lipschitz setting, we show that the final coalgebra for this functor does not exist. [ABSTRACT FROM AUTHOR]

Against the backdrop of the ever-improving Natural Language Inference (NLI) models, recent efforts have focused on the suitability of the current NLI datasets and on the feasibility of the NLI task as it is currently approached. Many of the recent studies have exposed the inherent human disagreements of the inference task and have proposed a shift from categorical labels to human subjective probability assessments, capturing human uncertainty. In this work, we show how neither the current task formulation nor the proposed uncertainty gradient are entirely suitable for solving the NLI challenges. Instead, we propose an ordered sense space annotation, which distinguishes between logical and common-sense inference. One end of the space captures non-sensical inferences, while the other end represents strictly logical scenarios. In the middle of the space, we find a continuum of common-sense, namely, the subjective and graded opinion of a "person on the street." To arrive at the proposed annotation scheme, we perform a careful investigation of the SICK corpus and we create a taxonomy of annotation issues and guidelines. We re-annotate the corpus with the proposed annotation scheme, utilizing four symbolic inference systems, and then perform a thorough evaluation of the scheme by fine-tuning and testing commonly used pre-trained language models on the re-annotated SICK within various settings. We also pioneer a crowd annotation of a small portion of the MultiNLI corpus, showcasing that it is possible to adapt our scheme for annotation by non-experts on another NLI corpus. Our work shows the efficiency and benefits of the proposed mechanism and opens the way for a careful NLI task refinement. [ABSTRACT FROM AUTHOR]

Finitary endofunctors of locally presentable categories are proved to have equational presentations. Special attention is being paid to the category of complete metric spaces and two endofunctors: the Hausdorff functor of all compact subsets and the Kantorovich functor of all tight measures. [ABSTRACT FROM AUTHOR]