> One edge of the graph (synthetic data): a person and the organization the store holds as their employer. PS500 is the id predicate.json gives employer, and its range is not an organization but a relationship type — so one edge is two rows sharing a relationshipId, one naming the kind of relationship and one pointing at the other entity. The forty-six relationship type classes in the table below exist to carry exactly that, which is what lets an edge hold a confidence of its own and be retracted later.

That is easily the sloppiest and least helpful explanations of edges and predicates I've ever read.