Where did I misplace my +100 wand? Great post, combinators are a not-so-hidden passion of mine and they inspire a lot of really practical applications in JavaScript and Ruby.
Thanks! I actually got the bug to write this post from reading your wonderful js combinator book[1] over the holiday, which reminded me that I also had a copy of To Mock a Mockingbird in my to read pile.
When I got to the bit where Smullyan describes the first sage bird (He explains: "This is quite simple ... for any bird x, Θx = M(Lx). Since x is fond of M(Lx) and M(Lx) = Θx, then x is fond of Θx, which means that Θ is a sage bird."), I felt like I had been hit by a brick wall as it was anything but simple for me, having previously grasped at understanding the y combinator.
Only by understanding the discrete moving parts was I able to finally wrap my head around what was going on. Like many others when I had my a-ha! moment I wanted to share.
Thank you for making content like this digestible!
