  What happens at times such as t2? These are times at which A exists or is present (is located). Note, furthermore, that, at t2, there is a posterior absence of &lt;A (for the prior absence of A is destroyed when A comes into existence), which we designate by ‘(&lt;A)&gt;’. There is also a prior absence of A&gt; (for the posterior absence of A does not yet exist), i.e.  ‘&lt;(A&gt;)’. The Manual of Reason (TSD 89E) records the older Naiyāyikas’ claim that these double absences must be identical with the original entity, on pain of an infinite regress. Thus: