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Version 5.3 (prerelease)

You can use, print, duplicate, share this book as much as you want. You can base your own notes on it and reuse parts if you keep the license the same. You can assume the license is either the CC-BY-NC-SA or CC-BY-SA, whichever is compatible with what you wish to do, your derivative works must use at least one of the licenses.

During the writing of these notes, the author was in part supported by NSF grant DMS-0900885 and DMS-1362337.

The date is the main identifier of version. The major version / edition number is raised only if there have been substantial changes. Edition number started at 5, that is, version 5.0, as it was not kept track of before.

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