If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
Notes for future OT posters:
1. Please add the 'open_thread' tag.
2. Check if there is an active Open Thread before posting a new one. (Immediately before; refresh the list-of-threads page before posting.)
3. Open Threads should be posted in Discussion, and not Main.
4. Open Threads should start on Monday, and end on Sunday.
I'm trying to wrap my mind around Hay's "Universal semimeasures", where he proves some very interesting equivalences.
In order to follow all the derivations, it would be very useful if there was a tool to draw binary trees and do some outlining of the branches, sub-trees, etc. Do you know of anything like that?