 An intermediate notion of equivalence that has proved central to the range, correlational, and code views on information is the relation of bisimulation between structures. A bisimulation relation between two graphs \(G\) and \(H\) (where both the arrows and nodes of the graphs are labelled) is a binary relation \(R\) between the nodes of the graphs with the property that whenever a node \(g\) of \(G\) is related to a node \(h\) of \(H\), then: 