 Exclusive disjunction and equivalence suggest two other basic relations among actions: symmetry and asymmetry (Royce 1905, 379–385; 1913a, 97–100). Exclusive disjunctions are symmetrical in that their order in relation to the disjunctive terms does not matter. That is, if \(A\) or \(\neg A\) is an exclusive disjunction, then \(\neg A\) or \(A\) is also. Equivalence is also symmetrical in that if \(A\) and \(B\) are equivalent, then \(B\) and \(A\) are also equivalent. In either case, the actions are not ordered with respect to each other. When actions are ordered such that \(A\) is antecedent to \(B\) (or vice versa), then the relation is asymmetrical.