Higher Recursion Theory

Author: Gerald E. Sacks
Publisher: Cambridge University Press
ISBN: 1316739465
Category: Mathematics
Page: N.A
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Since their inception, the Perspectives in Logic and Lecture Notes in Logic series have published seminal works by leading logicians. Many of the original books in the series have been unavailable for years, but they are now in print once again. This volume, the second publication in the Perspectives in Logic series, is an almost self-contained introduction to higher recursion theory, in which the reader is only assumed to know the basics of classical recursion theory. The book is divided into four parts: hyperarithmetic sets, metarecursion, α-recursion, and E-recursion. This text is essential reading for all researchers in the field.

General Recursion Theory

Author: Jens E. Fenstad
Publisher: Cambridge University Press
ISBN: 1107168163
Category: Mathematics
Page: 237
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Since their inception, the Perspectives in Logic and Lecture Notes in Logic series have published seminal works by leading logicians. Many of the original books in the series have been unavailable for years, but they are now in print once again. In this volume, the tenth publication in the Perspectives in Logic series, Jens E. Fenstad takes an axiomatic approach to present a unified and coherent account of the many and various parts of general recursion theory. The main core of the book gives an account of the general theory of computations. The author then moves on to show how computation theories connect with and unify other parts of general recursion theory. Some mathematical maturity is required of the reader, who is assumed to have some acquaintance with recursion theory. This book is ideal for a second course in the subject.

Bounded Queries in Recursion Theory

Author: William Levine,Georgia Martin
Publisher: Springer Science & Business Media
ISBN: 1461206359
Category: Computers
Page: 353
View: 5165

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One of the major concerns of theoretical computer science is the classifi cation of problems in terms of how hard they are. The natural measure of difficulty of a function is the amount of time needed to compute it (as a function of the length of the input). Other resources, such as space, have also been considered. In recursion theory, by contrast, a function is considered to be easy to compute if there exists some algorithm that computes it. We wish to classify functions that are hard, i.e., not computable, in a quantitative way. We cannot use time or space, since the functions are not even computable. We cannot use Turing degree, since this notion is not quantitative. Hence we need a new notion of complexity-much like time or spac~that is quantitative and yet in some way captures the level of difficulty (such as the Turing degree) of a function.

Recursion Theory

Computational Aspects of Definability
Author: Chi Tat Chong,Liang Yu
Publisher: Walter de Gruyter GmbH & Co KG
ISBN: 3110275643
Category: Mathematics
Page: 320
View: 2726

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This monograph presents recursion theory from a generalized and largely global point of view. A major theme is the study of the structures of degrees arising from two key notions of reducibility, the Turing degrees and the hyperdegrees, using ideas and techniques beyond those of classical recursion theory. These include structure theory, hyperarithmetic determinacy and rigidity, basis theorems, independence results on Turing degrees, as well as applications to higher randomness.

The Role of True Finiteness in the Admissible Recursively Enumerable Degrees

Author: Noam Greenberg
Publisher: American Mathematical Soc.
ISBN: 0821838857
Category: Mathematics
Page: 99
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When attempting to generalize recursion theory to admissible ordinals, it may seem as if all classical priority constructions can be lifted to any admissible ordinal satisfying a sufficiently strong fragment of the replacement scheme. We show, however, that this is not always the case. In fact, there are some constructions which make an essential use of the notion of finiteness which cannot be replaced by the generalized notion of $\alpha$-finiteness. As examples we discuss both codings of models of arithmetic into the recursively enumerable degrees, and non-distributive lattice embeddings into these degrees.We show that if an admissible ordinal $\alpha$ is effectively close to $\omega$ (where this closeness can be measured by size or by confinality) then such constructions may be performed in the $\alpha$-r.e. degrees, but otherwise they fail. The results of these constructions can be expressed in the first-order language of partially ordered sets, and so these results also show that there are natural elementary differences between the structures of $\alpha$-r.e. degrees for various classes of admissible ordinals $\alpha$. Together with coding work which shows that for some $\alpha$, the theory of the $\alpha$-r.e. degrees is complicated, we get that for every admissible ordinal $\alpha$, the $\alpha$-r.e. degrees and the classical r.e. degrees are not elementarily equivalent.

Fundamentals of Mathematical Logic

Author: Peter G. Hinman
Publisher: A K Peters/CRC Press
ISBN: 9781568812625
Category: Mathematics
Page: 896
View: 6382

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This introductory graduate text covers modern mathematical logic from propositional, first-order and infinitary logic and Gödel's Incompleteness Theorems to extensive introductions to set theory, model theory and recursion (computability) theory. Based on the author's more than 35 years of teaching experience, the book develops students' intuition by presenting complex ideas in the simplest context for which they make sense. The book is appropriate for use as a classroom text, for self-study, and as a reference on the state of modern logic.

Logic Colloquium 76

Proceedings of a Conference held in Oxford in July 1976
Author: R. O. Gandy,J. M. E. Hyland
Publisher: N.A
ISBN: 9780720422009
Category: Logic, Symbolic and mathematical
Page: 612
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Author: Vanderbilt University
Publisher: N.A
ISBN: 9780897918916
Category: Machine learning
Page: 338
View: 1727

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Constructivity and Computability in Historical and Philosophical Perspective

Author: Jacques Dubucs,Michel Bourdeau
Publisher: Springer
ISBN: 9401792178
Category: Philosophy
Page: 214
View: 6111

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Ranging from Alan Turing’s seminal 1936 paper to the latest work on Kolmogorov complexity and linear logic, this comprehensive new work clarifies the relationship between computability on the one hand and constructivity on the other. The authors argue that even though constructivists have largely shed Brouwer’s solipsistic attitude to logic, there remain points of disagreement to this day. Focusing on the growing pains computability experienced as it was forced to address the demands of rapidly expanding applications, the content maps the developments following Turing’s ground-breaking linkage of computation and the machine, the resulting birth of complexity theory, the innovations of Kolmogorov complexity and resolving the dissonances between proof theoretical semantics and canonical proof feasibility. Finally, it explores one of the most fundamental questions concerning the interface between constructivity and computability: whether the theory of recursive functions is needed for a rigorous development of constructive mathematics. This volume contributes to the unity of science by overcoming disunities rather than offering an overarching framework. It posits that computability’s adoption of a classical, ontological point of view kept these imperatives separated. In studying the relationship between the two, it is a vital step forward in overcoming the disagreements and misunderstandings which stand in the way of a unifying view of logic.

Recursively Enumerable Sets and Degrees

A Study of Computable Functions and Computably Generated Sets
Author: Robert I. Soare
Publisher: Springer Science & Business Media
ISBN: 9783540152996
Category: Mathematics
Page: 437
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..."The book, written by one of the main researchers on the field, gives a complete account of the theory of r.e. degrees. .... The definitions, results and proofs are always clearly motivated and explained before the formal presentation; the proofs are described with remarkable clarity and conciseness. The book is highly recommended to everyone interested in logic. It also provides a useful background to computer scientists, in particular to theoretical computer scientists." Acta Scientiarum Mathematicarum, Ungarn 1988 ..."The main purpose of this book is to introduce the reader to the main results and to the intricacies of the current theory for the recurseively enumerable sets and degrees. The author has managed to give a coherent exposition of a rather complex and messy area of logic, and with this book degree-theory is far more accessible to students and logicians in other fields than it used to be." Zentralblatt für Mathematik, 623.1988

Einführung in die mathematische Logik

Klassische Prädikatenlogik
Author: Hans Hermes
Publisher: Springer-Verlag
ISBN: 3322996425
Category: Technology & Engineering
Page: 208
View: 1667

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Das vorliegende, 1963 in erster Auflage erschienene Buch ist aus Vorlesungen hervorgegangen. Es soll eine Einführung in die klassische zweiwertige Prädikaten logik geben. Die Beschränkung auf die klassische Logik soll nicht besagen, daß diese Logik prinzipiell einen Vorzug vor anderen, nichtklassischen Logiken besitzt. Die klassische Logik empfiehlt sich jedoch als Einführung in die Logik wegen ihrer Einfachheit und als Fundament für die Anwendung deshalb, weil sie der klassischen Mathematik und damit den darauf aufgebauten exakten Wissenschaften zugrunde liegt. Das Buch wendet sich primär an Studierende der Mathematik, die in den An fängervorlesungen bereits einige grundlegende mathematische Begriffe, wie den Gruppenbegriff, kennengelernt haben. Der Leser soll dazu geführt werden, daß er die Vorteile einer Formalisierung einsieht. Der übergang von der Umgangssprache zu einer formalisierten Sprache, welcher erfahrungsgemäß gewisse Schwierigkeiten bereitet, wird eingehend besprochen und eingeübt. Die Analyse desmathemati schen Umgangs mit den grundlegenden mathematischen Strukturen führt in zwangloser Weise zum semantisch begründeten Folgerungsbegriff.

Computability and Models

Perspectives East and West
Author: Barry S. Cooper,Sergei S. Goncharov
Publisher: Springer Science & Business Media
ISBN: 1461507553
Category: Mathematics
Page: 375
View: 4572

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Science involves descriptions of the world we live in. It also depends on nature exhibiting what we can best describe as a high aLgorithmic content. The theme running through this collection of papers is that of the interaction between descriptions, in the form of formal theories, and the algorithmic content of what is described, namely of the modeLs of those theories. This appears most explicitly here in a number of valuable, and substantial, contributions to what has until recently been known as 'recursive model theory' - an area in which researchers from the former Soviet Union (in particular Novosibirsk) have been pre-eminent. There are also articles concerned with the computability of aspects of familiar mathematical structures, and - a return to the sort of basic underlying questions considered by Alan Turing in the early days of the subject - an article giving a new perspective on computability in the real world. And, of course, there are also articles concerned with the classical theory of computability, including the first widely available survey of work on quasi-reducibility. The contributors, all internationally recognised experts in their fields, have been associated with the three-year INTAS-RFBR Research Project "Com putability and Models" (Project No. 972-139), and most have participated in one or more of the various international workshops (in Novosibirsk, Heidelberg and Almaty) and otherresearch activities of the network.