1 These notes may change in the next few days (today is 30 Nov 2010).
2 The material here benefited from many discussions with Ken Shan.
4 ##[[Tree and List Zippers]]##
6 ##[[Coroutines and Aborts]]##
8 ##[[From Lists to Continuations]]##
10 ##[[List Monad as Continuation Monad]]##
12 ##[[Manipulating Trees with Monads]]##