دانلود کتاب برنامه‌های تفکر -مدل‌سازی منطقی و استدلال درباره زبان‌ها، داده‌ها، محاسبات و اجراها، ویرایش دوم

It is a great privilege for an author to be offered the opportunity to revise a book that was conceptualized more than a decade ago and subsequently elaborated in a period of more than five years. However, it also poses the obligation to seriously consider some basic questions, among them most important: Is the core topic still relevant? Are the fundamental ideas still sound? Is the organization still adequate? Should old material be dropped and/or new material be added? As for the core topic and the fundamental ideas: I am personally convinced as ever that the question of clear thinking about programs is as relevant as ever. This is also and in particular true in a time when more and more computer code is automatically generated by tools that are claimed to embed “artificial intelligence”. However, at their core, these tools rely on statistical principles that can not provide hard correctness guarantees: often the results seem alright, but some times they contain subtle errors; in the worst case, they are complete blunder. It is ultimately still up to us human beings as embodiments of “natural intelligence” to evaluate an automatically generated solution, judge its adequacy, and unveil its problems. Thus we have to be able to think about programs, within a suitable mental framework based on a language that is adequate to express our thoughts. The language of logic still seems the primary tool for this purpose. As for the organization and the material: The second part of the book has been carefullydesignedtoelaborateinthelanguageoflogicasequenceoftightlyintegrated other formal languages, starting with a language of specifying abstract datatypes, proceeding to a language of describing sequential programs, and culminating in a language for modeling concurrent systems, along with the methods needed for giving these languages a precise semantics and for reasoning about the artifacts described in these languages. For this purpose, the first part of the book presents the necessary foundations, in particular logic, set theory, and recursion theory; to these foundations the second part continuously refers. Even if some of the foundational material may be skipped on first reading, it is ultimately the basis for understanding the finer points of the later language formalizations; thus I refrained from putting the axe to any part of it. On the other side, considering the volume of the material already present, I (mostly) shied away from adding even more; any benefit of going into more depth in some aspects of the presentation would be counterbalanced by the detriment of losing the focus on the main messages that the book tries to convey. Ultimately, I decided to mostly concentrate in this new edition on improving not the extent but the quality of the presentation. Fortunately, having used a significant portion of the book in multiple iterations of my own courses, much of its content has been validated by repeated inspection, presentation, and discussion. However, by this process also multiple deficiencies have come to light, most of a minor nature, but also a few with larger significance; also re-reading the whole book from front to back with a fresh mind has helped to reveal some shortcomings. This second edition amends the deficits of the first one and thus represents a considerable advancement. Furthermore, while I refrained from adding to the core material (which, by its mathematical/logical nature, should essentially represent “eternal truths”), I’ve updated several of the (more time dependent) “software appendices” at the end of each chapter to take recent developments into account. In particular, I’ve added presentations of new software respectively of new features of software that was already discussed in the first edition.