 From a logical point of view, the Ockhamist approach to branching time bears a strong resemblance to the idea underlying the notion of a \(T\times W\) frame and the more general notion of a Kamp frame, discussed in Thomason (1984); the latter is technically equivalent to the notion of an Ockhamist frame introduced in Zanardo (1996). These kinds of frames build on a set of distinct possible worlds, each of which is endowed with an internal linear temporal structural, and assume a time-relative, historical accessibility relation between possible worlds. That is, overlap of histories is replaced by accessibility, and possible worlds are considered primitive elements whereas in branching time histories are defined in terms of instants. As a consequence, if we merge a frame consisting of historically related possible worlds into a single tree (replacing accessibility by identity), new histories may emerge that do not correspond to any of the possible worlds (for the construction, see e.g. Reynolds 2002).