My apologies. Yes, that's the correct reference. I learned about Paul Graham via several HN posts years ago and his explanation isn't unnecessarily complicated so I figured his work was widely known/understood.
P.S. when I put "dh0 response" into Google, the first link is Paul Graham's How to Disagree
Your Google-fu is better than mine. I tried "DH0", then "DH0 DH1", "dh disagreement", "dh levels", and it wasn't until "dh0 dh1 levels" that I got my answer. :)
Took me quite some time to find the magic combination of search terms. Of course HN assumes intimate knowledge with PG's works. ;)
http://www.paulgraham.com/disagree.html