 The way the Dignāga-Dharmakīrti school represent the mental process of reasoning is that one thinks: “A is B because of being C, like D.” More specifically, one invokes a logical reason C to prove the truth of the conclusion A is B; the example D, which is actually sometimes omitted, is a commonly acknowledged case of B-ness and C-ness that permits an individual to understand that all Cs are indeed Bs. The latter generalization is known as “pervasion” (vyāpti; Tibetan khyab pa) of C by B—a universally generalized material implication, for all x: if x is C then x is B, with the interesting feature that the quantification ranges over both actual and non-actual items. (The indispensability or dispensability of the example for one to ascertain/establish the pervasion becomes a hotly debated topic amongst later  theoreticians.[49])