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商品描述
This book was planned originally not as a work to be published, but as an excuse to buy a computer, incidentally to give me a chance to organize my own ideas n what measure theory every would-be analyst should learn, and to detail my approach to the subject. When it turned out that Springer-Verlag thought that the point of view in the book had general interest and offered to publish it, I was forced to try to write more clearly and search for errors. The search was productive. Readers will observe the stress on the following points. The application of pseudometric spaces. Pseudo metric, rather than metric spaces, are applied to obviate the artificial replacement of functions by equivalence classes, a replacement that makes the use of "almost everywhere" either improper or artificial. The words "function" and "the set on which a function has values at least E" can be taken literally in this book. Pseudometric space properties are applied in many contexts. For example, outer measures are used to pseudometrize classes of sets and the extension of a finite measure from an algebra to a 0" algebra is thereby reduced to finding the closure of a subset of a pseudo metric space.
商品描述(中文翻譯)
這本書最初並不是計劃作為一本出版的作品,而是作為購買電腦的藉口,順便給我一個機會來整理我對每位有志於成為分析師的學者應該學習的測度理論的想法,並詳細說明我對這個主題的看法。當Springer-Verlag認為這本書的觀點具有普遍興趣並提出出版時,我被迫嘗試更清晰地寫作並尋找錯誤。這次搜尋是富有成效的。讀者將注意到以下幾點的重點。偽度量空間的應用。使用偽度量空間而非度量空間,是為了避免將函數人為地替換為等價類,這種替換使得使用「幾乎處處」變得不當或人為。本書中的「函數」和「函數取值至少為E的集合」可以被字面理解。偽度量空間的性質在許多上下文中被應用。例如,外測度被用來對集合類進行偽度量化,並且將有限測度從一個代數擴展到0'代數的過程因此簡化為尋找偽度量空間子集的閉包。