Stephen Cook – författare

This book treats bounded arithmetic and propositional proof complexity from the point of view of computational complexity. The first seven chapters include the necessary logical background for the material and are suitable for a graduate course. Associated with each of many complexity classes are both a two-sorted predicate calculus theory, with induction restricted to concepts in the class, and a propositional proof system. The complexity classes range from AC0 for the weakest theory up to the polynomial hierarchy. Each bounded theorem in a theory translates into a family of (quantified) propositional tautologies with polynomial size proofs in the corresponding proof system. The theory proves the soundness of the associated proof system. The result is a uniform treatment of many systems in the literature, including Buss's theories for the polynomial hierarchy and many disparate systems for complexity classes such as AC0, AC0(m), TC0, NC1, L, NL, NC, and P.

This book treats bounded arithmetic and propositional proof complexity from the point of view of computational complexity. The first seven chapters include the necessary logical background for the material and are suitable for a graduate course. Associated with each of many complexity classes are both a two-sorted predicate calculus theory, with induction restricted to concepts in the class, and a propositional proof system. The complexity classes range from AC0 for the weakest theory up to the polynomial hierarchy. Each bounded theorem in a theory translates into a family of (quantified) propositional tautologies with polynomial size proofs in the corresponding proof system. The theory proves the soundness of the associated proof system. The result is a uniform treatment of many systems in the literature, including Buss's theories for the polynomial hierarchy and many disparate systems for complexity classes such as AC0, AC0(m), TC0, NC1, L, NL, NC, and P.

When the coronavirus pandemic took hold early in 2020, charities were among the first to respond to the resulting social and economic distress. But recent scandals and a more critical climate have overshadowed the vital role they play.What Have Charities Ever Done for Us? rebalances the debate, using case studies and interviews to illustrate how charities support people and communities, foster heritage and culture and pioneer responses to crucial social, ethical and environmental questions. It also sets the historical context, examines cases that have attracted criticisms, analyses the political response and considers how the governance, transparency and independence of charities could be improved.Charities at their best are the conscience of society and benefit most people at some point in their lives. This book brings to life the breadth and depth of their work and the contribution they make to social progress.

When the coronavirus pandemic took hold early in 2020, charities were among the first to respond to the resulting social and economic distress. But recent scandals and a more critical climate have overshadowed the vital role they play. What Have Charities Ever Done for Us? rebalances the debate, using case studies and interviews to illustrate how charities support people and communities, foster heritage and culture and pioneer responses to crucial social, ethical and environmental questions. It also sets the historical context, examines cases that have attracted criticisms, analyses the political response and considers how the governance, transparency and independence of charities could be improved. Charities at their best are the conscience of society and benefit most people at some point in their lives. This book brings to life the breadth and depth of their work and the contribution they make to social progress.

When the coronavirus pandemic took hold early in 2020, charities were among the first to respond to the resulting social and economic distress. But recent scandals and a more critical climate have overshadowed the vital role they play. What Have Charities Ever Done for Us? rebalances the debate, using case studies and interviews to illustrate how charities support people and communities, foster heritage and culture and pioneer responses to crucial social, ethical and environmental questions. It also sets the historical context, examines cases that have attracted criticisms, analyses the political response and considers how the governance, transparency and independence of charities could be improved. Charities at their best are the conscience of society and benefit most people at some point in their lives. This book brings to life the breadth and depth of their work and the contribution they make to social progress.

Five years on from its adoption in 1997 by the Object Management Group (OMG), the Uni?ed Modeling Language is the de facto standard for creating - agrammatic models of software systems. More than 100 books have been written about UML, and it is taught to students throughout the world. The de?nition of UML version 2 is well under way, and should be largely completed within the year. This will not only improve and enhance UML itself, including standard facilities for diagram interchange, but also make it fully integrated with other modeling technologies from the OMG, such as Meta-Object Facility (MOF) and XML Metadata Interchange (XMI). The Object Constraint Language, which has become an important vehicle for communicating detailed insights between UML researchers and practitioners, will have a much expanded speci?cation and be better integrated with the UML. The popularity of UML signi?es the possibility of a shift of immense prop- tions in the practice of software development, at least comparable to the shift from the use of assembly language to “third-generation” or “high-level” p- gramming languages. We dream of describing the behavior of software systems in terms of models, closely related to the needs of the enterprise being served, and being able to routinely translate these models automatically into executing p- grams on distributed computing systems. The OMG is promoting Model-Driven Architecture (MDA) as a signi?cant step towards this vision, and the MDA c- cept has received considerable support within the IT industry.

Five years on from its adoption in 1997 by the Object Management Group (OMG), the Uni?ed Modeling Language is the de facto standard for creating - agrammatic models of software systems. More than 100 books have been written about UML, and it is taught to students throughout the world. The de?nition of UML version 2 is well under way, and should be largely completed within the year. This will not only improve and enhance UML itself, including standard facilities for diagram interchange, but also make it fully integrated with other modeling technologies from the OMG, such as Meta-Object Facility (MOF) and XML Metadata Interchange (XMI). The Object Constraint Language, which has become an important vehicle for communicating detailed insights between UML researchers and practitioners, will have a much expanded speci?cation and be better integrated with the UML. The popularity of UML signi?es the possibility of a shift of immense prop- tions in the practice of software development, at least comparable to the shift from the use of assembly language to “third-generation” or “high-level” p- gramming languages. We dream of describing the behavior of software systems in terms of models, closely related to the needs of the enterprise being served, and being able to routinely translate these models automatically into executing p- grams on distributed computing systems. The OMG is promoting Model-Driven Architecture (MDA) as a signi?cant step towards this vision, and the MDA c- cept has received considerable support within the IT industry.