Tim Porter
crossed menagerie

Here is a more up-to-date version of the Crossed Menagerie (10 chapters). This version is slightly longer from the one that I have put up before. I have included a new section (in Chapter 2) which looks at the detailed derivation of the automorphism 2-group of a group as corresponding to the GAut(G), crossed module. I will add in later chapters as I become ‘happy’ with them.