This procedure of fixing the position of an event-particle shows that the aggregate of event-particles forms a four-dimensional manifold.

A finite event occupies a limited chunk of this manifold in a sense which I now proceed to explain.
Let e be any given event.

The manifold of event-particles falls into three sets in reference to e.

Each event-particle is a group of equal abstractive sets and each abstractive set towards its small-end is composed of smaller and smaller finite events.

When we select from these finite events which enter into the make-up of a given event-particle those which are small enough, one of three cases must occur.