44th International Colloquium on Automata, Languages, and Programming (ICALP 2017) (Ioannis Chatzigiannakis and Piotr Indyk and Fabian Kuhn and Anca Muscholl), volume 80 of Leibniz International Proceedings in Informatics (LIPIcs), pages 135:1-135:13, 2017, Schloss Dagstuhl–Leibniz-Zentrum fuer Informatik.