 This example illustrates that true futurist logics satisfying requirements which correspond to Belnap’s and Green’s semantical criteria may differ significantly from Prior’s Ockhamism. Even if we assume that (T1–4) should be valid and that (TRL1) and (TRL2′) should hold, we cannot be sure that (T5) is valid. On the other hand, some might of course intuitively find (T5) just as plausible as (T1–4), for which reason they would insist on a definition of \(C(t)\) according to which (T5) is valid. This, of course, means that the validity notion in (V) should be modified introducing further restrictions on the acceptable definitions of \(C(t)\). In order to ensure the validity of (T5) one might require that \(C(t') \subseteq C(t)\) for all \(t\) and \(t'\) with \(t \lt t'\). Another possibility is of course to insist on the Ockhamistic definition of \(C(t)\), i.e., \(C(t) = \{c \mid t \in c\}\), in which case TRL-validity would give the same result as Ockham-validity.