Multiway Graph
A multiway graph is a graph representing all possible branches of evolution for a system. Each node in the graph represents a possible complete state of the system at a particular step, while each edge corresponds to the evolution of one state to another as a result of an updating event. In a causally invariant system, every branching in the multiway system must ultimately reconverge (Wolfram). For example, the illustration above shows the multiway graph for the evaluation of the Fibonacci number F_2 using its standard recursive definition. The path followed by the Wolfram Language's standard evaluator is delineated in red.