Graph traversal automata for RDF queries #70
Description
This is a proof of concept demo for querying RDF graphs using simple automata that are themselves modelled in RDF, and inspired by work on ATNs from the 1970's. The starting point selects an initial node set, and this evolves as the state machine traverses the graph according to the state transition network. This is in a similar vein to SHACL and ShEX, but applied to queries instead of validation. The response is the set of triples the automaton has found which match the state transition network. Why do this? Because it allows for inference across graphs in ways that are hard to achieve with simple patterns (see issue #69).