I'm more inclined to say that Part 3 is the most important (transaction semantics) for other protocols development and that's what's on my mind right now. Part 5 would be the foundation of consensus. Thinking out loud, maybe I'm taking consensus for granted during the previous parts. In the overview of Part 1, I plan to explain all the mechanics, including distributed consensus, but without going into the details. Indeed, I feel it didn't work well last year. Maybe I should consider a lecture dedicated to consensus. Thanks.