According to Grothendieck, the notion of topos is "the bed or deep river where come to be married geometry and algebra, topology and arithmetic, mathematical logic and category theory, the world of the continuous and that of discontinuous or discrete structures". It is what he had "conceived of most broad to perceive with finesse, by the same language rich of geometric resonances, an "essence" which is common to situations most distant from each other, coming from one region or another of the vast universe of mathematical things". The aim of this book is to present a theory and a number of techniques which allow to give substance to Grothendieck's vision by building on the notion of classifying topos educed by categorical logicians. Mathematical theories (formalized within first-order logic) give rise to geometric objects called sites; the passage from sites to their associated toposes embodies the passage from the logical presentation of theories to their mathematical content, i.e. from syntax to semantics. The essential ambiguity given by the fact that any topos is associated in general with an infinite number of theories or different sites allows to study the relations between different theories, and hence the theories themselves, by using toposes as 'bridges' between these different presentations. The expression or calculation of invariants of toposes in terms of the theories associated with them or their sites of definition generates a great number of results and notions varying according to the different types of presentation, giving rise to a veritable mathematical morphogenesis.

This book is an attempt to give a systematic presentation of both logic and type theory from a categorical perspective, using the unifying concept of fibred category. Its intended audience consists of logicians, type theorists, category theorists and (theoretical) computer scientists.

Proceedings of a conference held at Centre de recherches mathematiques of the Universite de Montreal, June 18-20, 2009.

Category theory is a mathematical subject whose importance in several areas of computer science, most notably the semantics of programming languages and the design of programmes using abstract data types, is widely acknowledged. This book introduces category theory at a level appropriate for computer scientists and provides practical examples in the context of programming language design.

Introduction to concepts of category theory — categories, functors, natural transformations, the Yoneda lemma, limits and colimits, adjunctions, monads — revisits a broad range of mathematical examples from the categorical perspective. 2016 edition.

"Addresses the evolution of database management, technologies and applications along with the progress and endeavors of new research areas."--P. xiii.

This IMA Volume in Mathematics and its Applications TOWARDS HIGHER CATEGORIES contains expository and research papers based on a highly successful IMA Summer Program on n-Categories: Foundations and Applications. We are grateful to all the participants for making this occasion a very productive and stimulating one. We would like to thank John C. Baez (Department of Mathematics, University of California Riverside) and J. Peter May (Department of Ma- ematics, University of Chicago) for their superb role as summer program organizers and editors of this volume. We take this opportunity to thank the National Science Foundation for its support of the IMA. Series Editors Fadil Santosa, Director of the IMA Markus Keel, Deputy Director of the IMA v PREFACE DEDICATED TO MAX KELLY, JUNE 5 1930 TO JANUARY 26 2007. This is not a proceedings of the 2004 conference “n-Categories: Fo- dations and Applications” that we organized and ran at the IMA during the two weeks June 7–18, 2004! We thank all the participants for helping make that a vibrant and inspiring occasion. We also thank the IMA sta? for a magni?cent job. There has been a great deal of work in higher c- egory theory since then, but we still feel that it is not yet time to o?er a volume devoted to the main topic of the conference.

Röntgenbefund und die sich in ihm widerspiegelnde pathologische Anatomie sind neben dem klinischen Bild die wichtigsten Säulen, auf denen die Diagnostik von Knochengeschwülsten und geschwulstähnlichen Läsionen beruht. Radiologen und Pathologen stellen in diesem Buch Klinik, Radiologie und Histolgie der verschiedenen Knochenläsionen am Gliedmaßen- und Achsenskelett umfassend und synoptisch dar. Das umfangreiche Material resultiert aus einer fünfzehnjährigen interdisziplinären Zusammenarbeit. In einem einleitenden Kapitel werden die verschiedenen radiologischen (konventionelles Röntgenbild, CT, Kernspintomographie, Angiographie, transkutane Biopsie) und histologischen Untersuchungstechniken und ihre Wertigkeit beschrieben. Der radiologischen Befundungsmethodik von Knochengeschwülsten u.a. mit Hilfe der Lodwick-Graduierung und einem neueren Staging-System für Knochengeschwülste werden eigene Kapitel gewidmet. Im speziellen Teil des Buches erfolgt die Darstellung der einzelnen benignen und malignen Knochengeschwülste in einer systematischen Untergliederung in ihre Häufigkeit, Lokalisation, Alters- und Geschlechtsprädilektion, Klinik und Prognose, Histologie, Radiologie und Differentialdiagnose. Besonders die unter den Knochengeschwülsten und tumorähnlichen Läsionen häufig vorkommenenden Entitäten sind mit einem umfassenden Bildmaterial ausgestattet, um dem breiten Spektrum ihrer Morphologie gerecht zu werden. Durch das Verständnis klinischer, radiologischer und pathologisch-anatomischer Befunde werden Diagnostik und Therapie der Skelettläsionen sehr erleichtert. Die synoptische Art der Darstellung macht dieses Buch für alle Disziplinen, die sich mit Knochentumoren befassen, zu einem idealen Nachschlagewerk.