I was about to post your number 3 before I saw it here. Here's a link to it: htt...

		FredrikMeyer on Nov 15, 2017 \| parent \| context \| favorite \| on: Ask HN: What are some interesting papers in CS for... I was about to post your number 3 before I saw it here. Here's a link to it: http://www-formal.stanford.edu/jmc/recursive.html