Efficient Instance Retrieval with Standard and Relational Path Indexing

Path indexing is a family of indexing techniques that can support instance retrieval, which is the core of any implementation of backward demodulation. We propose a number of powerful optimisations to standard path indexing. We also describe a novel flexible framework, called relational path indexing, that combines path indexing with relational joins. We illustrate the flexibility of relational path indexing by sketching how to adapt the scheme to instance retrieval modulo commutativity and backward subsumption on multi-literal clauses.