Philip Bille, Travis Gagie, Inge Li Gørtz, Nicola Prezza·2017-11-20·via cs.DS updates on arXiv.org
In this paper we give an infinite family of strings for which the length of the Lempel-Ziv'77 parse is a factor $Ω(\log n/\log\log n)$ smaller than the smallest run-length grammar.