Before revision:  Our index locates path occurrences in constant time each and takes 2n + o(n) + O(r log n) \leq 2n + o(n)  + O(H log n) bitsof space: the reporting timeis optimal and the locate machinery fits within compressed space on top of the succinct topology .
After revision:  Our index locates path occurrences in constant time each and takes 2n + o(n) + O(r log n) \leq 2n + o(n) bits, where n is the number of nodes, allows locating the occ occurrences of a pattern of length m in nearly-optimal O(m\log\sigma + O(H log n) bitsof space: the reporting timeis optimal and the locate machinery fits within compressed space on top of the succinct topology .