67,330 research outputs found
p-topological and p-regular: dual notions in convergence theory
The natural duality between "topological" and "regular," both considered as
convergence space properties, extends naturally to p-regular convergence
spaces, resulting in the new concept of a p-topological convergence space.
Taking advantage of this duality, the behavior of p-topological and p-regular
convergence spaces is explored, with particular emphasis on the former, since
they have not been previously studied. Their study leads to the new notion of a
neighborhood operator for filters, which in turn leads to an especially simple
characterization of a topology in terms of convergence criteria. Applications
include the topological and regularity series of a convergence space.Comment: 12 pages in Acrobat 3.0 PDF forma
Topological properties of concept spaces (full version)
AbstractBased on the observation that the category of concept spaces with the positive information topology is equivalent to the category of countably based T0 topological spaces, we investigate further connections between the learning in the limit model of inductive inference and topology. In particular, we show that the “texts” or “positive presentations” of concepts in inductive inference can be viewed as special cases of the “admissible representations” of computable analysis. We also show that several structural properties of concept spaces have well known topological equivalents. In addition to topological methods, we use algebraic closure operators to analyze the structure of concept spaces, and we show the connection between these two approaches. The goal of this paper is not only to introduce new perspectives to learning theorists, but also to present the field of inductive inference in a way more accessible to domain theorists and topologists
Prototypes, Poles, and Topological Tessellations of Conceptual Spaces
Abstract. The aim of this paper is to present a topological method for constructing
discretizations (tessellations) of conceptual spaces. The method works for a class of
topological spaces that the Russian mathematician Pavel Alexandroff defined more than
80 years ago. Alexandroff spaces, as they are called today, have many interesting
properties that distinguish them from other topological spaces. In particular, they exhibit
a 1-1 correspondence between their specialization orders and their topological structures.
Recently, a special type of Alexandroff spaces was used by Ian Rumfitt to elucidate the
logic of vague concepts in a new way. According to his approach, conceptual spaces such
as the color spectrum give rise to classical systems of concepts that have the structure
of atomic Boolean algebras. More precisely, concepts are represented as regular open
regions of an underlying conceptual space endowed with a topological structure.
Something is subsumed under a concept iff it is represented by an element of the
conceptual space that is maximally close to the prototypical element p that defines that
concept. This topological representation of concepts comes along with a representation
of the familiar logical connectives of Aristotelian syllogistics in terms of natural settheoretical
operations that characterize regular open interpretations of classical Boolean
propositional logic.
In the last 20 years, conceptual spaces have become a popular tool of dealing with a
variety of problems in the fields of cognitive psychology, artificial intelligence, linguistics
and philosophy, mainly due to the work of Peter Gärdenfors and his collaborators. By using
prototypes and metrics of similarity spaces, one obtains geometrical discretizations of
conceptual spaces by so-called Voronoi tessellations. These tessellations are extensionally
equivalent to topological tessellations that can be constructed for Alexandroff spaces.
Thereby, Rumfitt’s and Gärdenfors’s constructions turn out to be special cases of an
approach that works for a more general class of spaces, namely, for weakly scattered
Alexandroff spaces. This class of spaces provides a convenient framework for conceptual
spaces as used in epistemology and related disciplines in general. Alexandroff spaces are
useful for elucidating problems related to the logic of vague concepts, in particular they
offer a solution of the Sorites paradox (Rumfitt). Further, they provide a semantics for the
logic of clearness (Bobzien) that overcomes certain problems of the concept of higher2
order vagueness. Moreover, these spaces help find a natural place for classical syllogistics
in the framework of conceptual spaces. The crucial role of order theory for Alexandroff
spaces can be used to refine the all-or-nothing distinction between prototypical and nonprototypical
stimuli in favor of a more fine-grained gradual distinction between more-orless
prototypical elements of conceptual spaces. The greater conceptual flexibility of the
topological approach helps avoid some inherent inadequacies of the geometrical approach,
for instance, the so-called “thickness problem” (Douven et al.) and problems of selecting
a unique metric for similarity spaces. Finally, it is shown that only the Alexandroff account can deal with an issue that is gaining more and more importance for the theory of conceptual spaces, namely, the role that digital conceptual spaces play in the area of artificial intelligence, computer science and related disciplines.
Keywords: Conceptual Spaces, Polar Spaces, Alexandroff Spaces, Prototypes, Topological Tessellations, Voronoi Tessellations, Digital Topology
Topological properties of spaces ordered by preferences
In this paper, we analyze the main topological properties of a
relevant class of topologies associated with spaces ordered by preferences
(asymmetric, negatively transitive binary relations). This class consists
of certain continuous topologies which include the order topology. The
concept of saturated identification is introduced in order to provide a
natural proof of the fact that all these spaces possess topological
properties analogous to those of linearly ordered topological spaces,
inter alia monotone and hereditary normality, and complete regularity
Closed injective systems and its fundamental limit spaces
In this article we introduce the concept of limit space and fundamental limit
space for the so-called closed injected systems of topological spaces. We
present the main results on existence and uniqueness of limit spaces and
several concrete examples. In the main section of the text, we show that the
closed injective system can be considered as objects of a category whose
morphisms are the so-called cis-morphisms. Moreover, the transition to
fundamental limit space can be considered a functor from this category into
category of topological spaces. Later, we show results about properties on
functors and counter-functors for inductive closed injective system and
fundamental limit spaces. We finish with the presentation of some results of
characterization of fundamental limite space for some special systems and the
study of so-called perfect properties.Comment: 18 pages, 2 figure
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