Just wanted to thank you for that information. And also give you some feedback on commenting. The HN commennt guidelines mention to not insinuate someone hasn't read the article. What you might not know is that I did read the section you quote, but I did not know enough to resolve it myself without asking a question. When I read that you didn't think I had, I felt you were saying, the answer would be obvious if you had read it. That hurt because it was like saying my question was stupid, which I don't like and I don't want to feel discouraged from asking questions in future. Anyway, thanks for your information, and I hope this feedback is useful.