 On this kind of view, what it takes for a system of structural equations to correctly represent a network of token influence is for some corresponding counterfactuals to be true. There is a weaker and a stronger version of this requirement. On the stronger version, we require that all of the (infinitely many) counterfactuals which can be derived from the model (via the interventionist procedure outlined in the previous subsection) are true. On the weaker version, we require only the more limited class of counterfactuals which say that, were any subset of the variables to have their values set via an intervention, the equations for the non-intervened upon variables would continue to be true. For illustration, take the following system of equations,