[math-fun] Draft of short piece on Ehrenfeucht-Mycielski sequence

I'd welcome comments on http://mathenchant.org/em-draft2.pdf (I already found one typo re-reading it, where I wrote "Thanks for Joel Spencer" instead of "Thanks to Joel Spencer", but it's time for me to let go of it and see what other people think.) As in the case of the two previous short pieces I posted, this piece will live two lives: first as a short Big Internet Math-Off pitch, then as a longer Mathematical Enchantments essay. There's plenty of time for you to send me feedback that'll affect the latter version, since that won't be going out until late 2019; but the BIMO pitch needs to be sent to Christian Lawson-Perfect by the 13th, so that he can post it early on the 15th. Thanks, Jim Propp