Decision Problems for Equational Theories of Relation Algebras

Decision Problems for Equational Theories of Relation Algebras PDF Author: H. Andréka
Publisher: American Mathematical Soc.
ISBN: 0821805959
Category : Mathematics
Languages : en
Pages : 146

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Book Description
"We prove that any variety of relation algebras which contains an algebra with infinitely many elements below the identity, or which contains the full group relation algebra on some infinite group (or on arbitrarily large finite groups), must have an undecidable equational theory. Then we construct an embedding of the lattice of all subsets of the natural numbers into the lattice of varieties of relation algebras such that the variety correlated with a set [italic capital]X of natural numbers has a decidable equational theory if and only if [italic capital]X is a decidable (i.e., recursive) set. Finally, we construct an example of an infinite, finitely generated, simple, representable relation algebra that has a decidable equational theory.'' -- Abstract.

Decision Problems for Equational Theories of Relation Algebras

Decision Problems for Equational Theories of Relation Algebras PDF Author: H. Andréka
Publisher: American Mathematical Soc.
ISBN: 0821805959
Category : Mathematics
Languages : en
Pages : 146

Get Book Here

Book Description
"We prove that any variety of relation algebras which contains an algebra with infinitely many elements below the identity, or which contains the full group relation algebra on some infinite group (or on arbitrarily large finite groups), must have an undecidable equational theory. Then we construct an embedding of the lattice of all subsets of the natural numbers into the lattice of varieties of relation algebras such that the variety correlated with a set [italic capital]X of natural numbers has a decidable equational theory if and only if [italic capital]X is a decidable (i.e., recursive) set. Finally, we construct an example of an infinite, finitely generated, simple, representable relation algebra that has a decidable equational theory.'' -- Abstract.

Decision Problems for Equational Theories of Relation Algebras

Decision Problems for Equational Theories of Relation Algebras PDF Author: H. Andréka
Publisher: American Mathematical Soc.
ISBN: 9780821863275
Category : Mathematics
Languages : en
Pages : 148

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Book Description
This work presents a systematic study of decision problems for equational theories of algebras of binary relations (relation algebras). For example, an easily applicable but deep method, based on von Neumann's coordinatization theorem, is developed for establishing undecidability results. The method is used to solve several outstanding problems posed by Tarski. In addition, the complexity of intervals of equational theories of relation algebras with respect to questions of decidability is investigated. Using ideas that go back to Jonsson and Lyndon, the authors show that such intervals can have the same complexity as the lattice of subsets of the set of the natural numbers. Finally, some new and quite interesting examples of decidable equational theories are given. The methods developed in the monograph show promise of broad applicability. The provide researchers in algebra and logc with a new arsenal of techniques for resolving decision questions in various domains of algebraic logic.

Hajnal Andréka and István Németi on Unity of Science

Hajnal Andréka and István Németi on Unity of Science PDF Author: Judit Madarász
Publisher: Springer Nature
ISBN: 3030641872
Category : Philosophy
Languages : en
Pages : 513

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Book Description
This book features more than 20 papers that celebrate the work of Hajnal Andréka and István Németi. It illustrates an interaction between developing and applying mathematical logic. The papers offer new results as well as surveys in areas influenced by these two outstanding researchers. They also provide details on the after-life of some of their initiatives. Computer science connects the papers in the first part of the book. The second part concentrates on algebraic logic. It features a range of papers that hint at the intricate many-way connections between logic, algebra, and geometry. The third part explores novel applications of logic in relativity theory, philosophy of logic, philosophy of physics and spacetime, and methodology of science. They include such exciting subjects as time travelling in emergent spacetime. The short autobiographies of Hajnal Andréka and István Németi at the end of the book describe an adventurous journey from electric engineering and Maxwell’s equations to a complex system of computer programs for designing Hungary’s electric power system, to exploring and contributing deep results to Tarskian algebraic logic as the deepest core theory of such questions, then on to applications of the results in such exciting new areas as relativity theory in order to rejuvenate logic itself.

Logic as Algebra

Logic as Algebra PDF Author: Paul Halmos
Publisher: American Mathematical Soc.
ISBN: 1470451131
Category : Education
Languages : en
Pages : 153

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Book Description
Here is an introduction to modern logic that differs from others by treating logic from an algebraic perspective. What this means is that notions and results from logic become much easier to understand when seen from a familiar standpoint of algebra. The presentation, written in the engaging and provocative style that is the hallmark of Paul Halmos, from whose course the book is taken, is aimed at a broad audience, students, teachers and amateurs in mathematics, philosophy, computer science, linguistics and engineering; they all have to get to grips with logic at some stage. All that is needed to understand the book is some basic acquaintance with algebra.

Cyclic Feedback Systems

Cyclic Feedback Systems PDF Author: Tomáš Gedeon
Publisher: American Mathematical Soc.
ISBN: 0821807838
Category : Mathematics
Languages : en
Pages : 89

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Book Description
Explores the global dynamics of a class of ordinary differential equations called cyclic feedback systems. The global dynamics is described by a Morse decomposition of the global attractor, defined with the help of a discrete Lyapunov function. A three-dimensional system of ODE's with two linear equations is constructed, such that the invariant set is at least as complicated as a suspension of a full shift on two symbols. No index. Annotation copyrighted by Book News, Inc., Portland, OR

Higher Initial Ideals of Homogeneous Ideals

Higher Initial Ideals of Homogeneous Ideals PDF Author: Gunnar Fløystad
Publisher: American Mathematical Soc.
ISBN: 0821808532
Category : Mathematics
Languages : en
Pages : 82

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Book Description
Given a homogeneous ideal I and a monomial order, the initials ideal in (I) can be formed. The initial idea gives information about I, but quite a lot of information is also lost. The author remedies this by defining a series of higher initial ideals of a homogenous ideal, and considers the case when I is the homogenous ideal of a curve in P3 and the monomial order is reverse lexicographic. No index. Annotation copyrighted by Book News, Inc., Portland, OR

Generalized Minkowski Content, Spectrum of Fractal Drums, Fractal Strings and the Riemann Zeta-Functions

Generalized Minkowski Content, Spectrum of Fractal Drums, Fractal Strings and the Riemann Zeta-Functions PDF Author: Christina Q. He
Publisher: American Mathematical Soc.
ISBN: 0821805975
Category : Mathematics
Languages : en
Pages : 114

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Book Description
This memoir provides a detailed study of the effect of non power-like irregularities of (the geometry of) the fractal boundary on the spectrum of "fractal drums" (and especially of "fractal strings"). In this work, the authors extend previous results in this area by using the notionof generalized Minkowski content which is defined through some suitable "gauge functions" other than power functions. (This content is used to measure the irregularity (or "fractality") of the boundary of an open set in R]n by evaluating the volume of its small tubular neighborhoods). In the situation when the power function is not the natural "gauge function", this enables the authors to obtain more precise estimates, with a broader potential range of applications than in previous papers of the second author and his collaborators. This text will also be of interest to those working in mathematical physics.

Nonlinear Eigenvalues and Analytic-Hypoellipticity

Nonlinear Eigenvalues and Analytic-Hypoellipticity PDF Author: Ching-Chau Yu
Publisher: American Mathematical Soc.
ISBN: 0821807846
Category : Mathematics
Languages : en
Pages : 106

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Book Description
Explores the failure of analytic-hypoellipticity of two partial differential operators. The operators are sums of squares of real analytic vector fields and satisfy Hormander's condition. By reducing to an ordinary differential operator, the author shows the existence of non-linear eigenvalues, which is used to disprove analytic- hypoellipticity of the original operators. No index. Annotation copyrighted by Book News, Inc., Portland, OR

Treelike Structures Arising from Continua and Convergence Groups

Treelike Structures Arising from Continua and Convergence Groups PDF Author: Brian Hayward Bowditch
Publisher: American Mathematical Soc.
ISBN: 0821810030
Category : Mathematics
Languages : en
Pages : 101

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Book Description
This book is intended for graduate students and research mathematicians working in group theory and generalizations

Handbook of Philosophical Logic

Handbook of Philosophical Logic PDF Author: Dov M. Gabbay
Publisher: Springer Science & Business Media
ISBN: 940170452X
Category : Philosophy
Languages : en
Pages : 417

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Book Description
It is with great pleasure that we are presenting to the community the second edition of this extraordinary handbook. It has been over 15 years since the publication of the first edition and there have been great changes in the landscape of philosophical logic since then. The first edition has proved invaluable to generations of students and researchers in formal philosophy and language, as weIl as to consumers of logic in many applied areas. The main logic artiele in the Encyelopaedia Britannica 1999 has described the first edition as 'the best starting point for exploring any of the topics in logic'. We are confident that the second edition will prove to be just as good. ! The first edition was the second handbook published for the logic commu nity. It followed the North Holland one volume Handbook 0/ Mathematical Logic, published in 1977, edited by the late Jon Barwise. The four volume Handbook 0/ Philosophical Logic, published 1983-1989 came at a fortunate at the evolution of logic. This was the time when logic temporal junction was gaining ground in computer science and artificial intelligence cireles. These areas were under increasing commercial pressure to provide devices which help andjor replace the human in his daily activity. This pressure required the use of logic in the modelling of human activity and organisa tion on the one hand and to provide the theoretical basis for the computer program constructs on the other.