 Logical Connectives and De Morgan’s Laws. The Manual of Reason touches on the meaning of conjunctive and disjunctive absence, i.e. absence of (both A and B) (ubhayābhāva) and absence of (either A or B) (anyatarābhāva). It observes that an awareness that two pots are absent is consistent with an awareness that one pot is present (and the other absent). In fact, as Ingalls shows (1951: 63–67) the Nyāya recognised the validity of two general equations: