To be fair, Roundy's idea of commutation was novel in 2002 (unless it was a reinvention of something earlier, which wouldn't surprise me) whether or not it was

To be fair, Roundy's idea of commutation was novel in 2002 (unless it was a reinvention of something earlier, which wouldn't surprise me) whether or not it was done right then. I'm happy if Pijul improves something which definitely simplifies workflows and doesn't get me confused after 30 years of revision control and sometimes resorting to diffs.