See also “Seemingly impossible functional programs” by Martin Escardo, from 2007 ([1], also at [2]). It covers similar ground and is referenced at the bottom o

See also “Seemingly impossible functional programs” by Martin Escardo, from 2007 ([1], also at [2]). It covers similar ground and is referenced at the bottom of the article (along with three other references also by Martín Escardó), but I thought it worth mentioning explicitly because I remember reading it many years ago and finding it really fun. [1]: http://math.andrej.com/2007/09/28/seemingly-impossible-functional-programs/ http://math.andrej.com/2007/09/28/seemingly-impossible-funct... [2]: http://www.cs.bham.ac.uk/~mhe/papers/seemingly-impossible.html http://www.cs.bham.ac.uk/~mhe/papers/seemingly-impossible.ht...