 Avicenna is keen to point out on various occasions throughout the treatment of conditionals in the Qiyās that what matters are the quantificational aspects of the relation between antecedent and consequent (the nisba or the ḥukm), not the quantity and quality of the antecedent and consequent themselves. In particular, he vigorously rejects the view that the contradictory of a conditional statement is a conditional statement of the same quality and quantity whose consequent is denied. In his view, the contradictory of (a-\(\mathbb{C}\))aa is  (o-\(\mathbb{C}\))aa, not (a-\(\mathbb{C}\))ao. In other words, “Always, if every A is B, then every C is D” is contradicted by “Not always, if every A is B, then every C is D” and not by “Always, if every A is B, then not every C is D” which is in fact a stronger statement equivalent to its contrary, namely  (e-\(\mathbb{C}\))aa (“Never, if every A is B, then every C is D”).[10] On the other hand, (o-\(\mathbb{C}\))aa is logically equivalent to (i-\(\mathbb{C}\))ao (“Sometimes, if every A is B, then not every C is D”), which is therefore another contradictory of (a-\(\mathbb{C}\))aa. A set of basic relations is represented in the following diagram