 are not symmetric in the following sense: an instantiation of a cluster is sufficient for \(E\), but an instantiation of \(E\) is generally not sufficient to determine which cluster is instantiated. An instantiation of \(E\) does not determine whether \(C_1 \land C_2\) or \(D_1\) is instantiated. An instantiation of \(E\) only determines the whole disjunction of minimally sufficient clusters. This non-symmetry may be exploited to establish a notion of causal priority or the direction of causation.