Modular Path Queries with Arithmetic

We propose a new approach to querying graph databases. Our balances competing goals of expressive power, language clarity and computational complexity. A distinctive feature our is the ability express properties minimal (e.g. shortest) maximal most valuable) paths satisfying given criteria. To complex in modular way, we introduce labelling-generating ontologies. The resulting formalism computationally attractive - queries can be answered non-deterministic logarithmic space size database.