 The Helsinki model consists of three primitive endogenous nodes, each node comprising a meeting point of three edges, with two “internal” edges linking the three nodes and five “external” edges. Each edge has one of three “flavors”, A, B, or C. The system is temporally oriented with three exogenous nodes, each joined to a single edge, representing system “inputs” (preparations/interventions), and two system “outputs” (measurement outcomes/observations) joined to the remaining two edges. The two internal edges represent hidden flavors that cannot be directly controlled or observed. There are two basic rules that govern the dynamics of this toy system: (i) each node must be strictly inhomogeneous—i.e., comprising three edges of different flavors—or strictly homogeneous—i.e., three edges of the same flavor, and (ii) successive homogeneous nodes are prohibited.