(Hardcover - English - 9781584887935)
strong Presents Results from a Very Active Area of Research strong Exploring an active area of mathematics that studies the complexity of equivalence relations and classification problems, strong Invariant Descriptive Set Theory strong presents an introduction to the basic concepts, methods, and results of this theory. It brings together techniques from various areas of mathematics, such as algebra, topology, and logic, which have diverse applications to other fields. After reviewing classical and effective descriptive set theory, the text studies Polish groups and their actions. It then covers Borel reducibility results on Borel, orbit, and general def ..