graph queries
Queries on graph can represented using differents languages. An interesting introduction of topic is given in DBLP:series/synthesis/2018Bonifati chapter 3.
Regular path queries (RPQ)
They are the queries defined by a regular language \(L\) on the edges of the graph returning the pair of vertexes \((x, y)\) such that there is a path from \(x\) to \(y\) belonging to \(L\).
2RPQ is an extension of RPQ where \(L\) is a regular language on the edges and their inverse.
