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) + occ) time, where \sigma is the alphabet's size. Our solution consists in sampling O(r) nodes that can be used as "anchor points" during the locate process. Once obtained the pre-order identifier of the first pattern occurrence (in co-lexicographic order), we show that a constant number of constant-time jumps between those anchor points lead to the identifier of the next pattern occurrence, thus enabling locating in optimal O(1) time per occurrence .