48th International Colloquium on Automata, Languages, and Programming, ICALP 2021, July 12-16, 2021, Glasgow, Scotland (Virtual Conference) (Nikhil Bansal and Emanuela Merelli and James Worrell), volume 198 of LIPIcs, pages 72:1-72:17, 2021, Schloss Dagstuhl - Leibniz-Zentrum für Informatik.