On query answering in description logics with number restrictions on transitive roles

We study query answering in the description logic SQ supporting number restrictions on both transitive and non-transitive roles. Our main contributions are (i) a tree-like model property for SQ knowledge bases and, building upon this, (ii) an automata based decision procedure for answering two-way regular path queries, which gives a 3ExpTime upper bound

Imaginative Animals. Leibniz's Logic of Imagination

Through the reconstruction of Leibniz's theory of the degrees of knowledge, this e-book investigates and explores the intrinsic relationship of imagination with space and time. The inquiry into this relationship defines the logic of imagination that characterizes both human and non-human animals, albeit differently, making them two different species of imaginative animals. Lucia Oliveri explains how the emergence of language in human animals goes hand in hand with the emergence of thought and a different form of rationality constituted by logical inferences based on identity and contradiction, principles that are out of reach of the imagination. The e-book concludes that the presence of innate principles in human animals transforms the way in which they sense-perceive the world, thereby constantly increasing the distinction between human and non-human animals. Keywords: human and non-human animals, Leibniz and Locke on ideas, Leibniz on bodies, Leibniz on conceivability, Leibniz on degrees of knowledge, Leibniz on degrees of perception, Leibniz on innate ideas, Leibniz on modality, Leibniz on similarity and congruence, Leibniz on space and time, Leibniz’s philosophy of language, theory of type

Effervescent Presentism: An Outline and Defence

This dissertation is an investigation of presentism, the thesis that all and only present things exist. Though an increasingly popular topic, it is ill-understood. The investigation has three main aims. Firstly, to improve understanding of the presentist thesis by distinguishing, outlining, and exploring various plausible competing interpretations ('theories'). Secondly, to motivate presentism and weigh-up competing presentist theories against theory-choice criteria. Thirdly, to develop and defend a preferred, and novel, presentist variant: Effervescent Presentism. What the presentist thesis amounts to depends on how key concepts employed in its statement are interpreted; distinct interpretations each specify competing description of temporal reality. Specifically, the focus is on how we understand existence and the A-determinations—presentness, together with its related notions of pastness and futurity. The dissertation divides into three parts. In Part One, I establish a fixed, tensed, conception of existence avoiding the triviality charge against presentism, and permitting a robust distinction between mere temporal variation and metaphysical change. Then, having outlined a broadly pragmatic methodology, I provide some motivations for presentism, focusing on its explanatory virtues for the nature of causation. This justifies interest in the project, but also establishes a distinguishing criterion for presentist theories: how well they support those motivations. In Part Two, I outline alternative presentist theories, and introduce potential theory-choice criteria to suggest plausible interpretative directions and preferentially distinguish theories. Part Three then introduces, develops, and defends effervescent presentism, in greater detail due to its preference and complexity. It delivers an understanding of presentness in terms of a law-based account of causal activity. This ties time intimately to causation, and consequently supports the presentist motivations from Part One and the need to unify time. The research should demonstrate the tenability of effervescent presentism, and its worthiness of wider consideration