 The relations among disjunctions and conditionals, a theme of obvious interest from the standpoint of modern logic, reflect the complexity of the above distinctions. Avicenna investigates relations such as, for instance, the triangulation between (a-\(\mathbb{D}\)), (a-\(\mathbb{C}\)), and (e-\(\mathbb{D}\)) propositions (Qiyās VII.2, 381.11–17):