Grammar-compressed indexes with logarithmic search time

Let a text T[1..n] be the only string generated by context-free grammar with g (terminal and nonterminal) symbols, of size G (measured as sum lengths right-hand sides rules). Such grammar, called grammar-compressed representation T, can encoded using Glg⁡G bits. We introduce first index that uses O(Glg⁡n) bits (precisely, Glg⁡n+(2+ϵ)Glg⁡g for any constant ϵ>0) find occ occurrences patterns P[1..m] in time O((m2+occ)lg⁡G). implement demonstrate its practicality comparison state art, on highly repetitive collections.