What caught my attention about your site is that I know from experience how hard it is to create a fork of gwern.net: https://www.shawwn.com/swarm I noticed lots of little details in yours, like the fact that the anonymous feedback form is different, and that you exported your logo with potrace. (Killer logo by the way!) All of that took a lot of thought and effort, and it was a delightful surprise to see that someone else did it independently. It'd be neat to compare notes with you!
Thanks a lot for the thoughtful content, and the tree of concepts. I don't have nearly as much training in math, so it was quite helpful. :)
Not a problem ... I'm involved with outreach, enrichment, and enhancement, so creating a DiGraph or concepts, although impossible, would be an excellent goal. I know groups that are making progress towards it for the UK school curriculum, but it's hard, and I'm not entirely sure that what they're doing will turn out to be useful in the way(s) I'd hope.