I will therefore use the name 'event-particles' for the ideal minimum limits to events.

Thus an event-particle is an abstractive element and as such is a group of abstractive sets; and a point--namely a point of timeless space--will be a class of event-particles.
Furthermore there is a separate timeless space corresponding to each separate temporal series, that is to each separate family of durations.
We will come back to points in timeless spaces later.

I merely mention them now that we may understand the stages of our investigation.

The totality of event-particles will form a four-dimensional manifold, the extra dimension arising from time--in other words--arising from the points of a timeless space being each a class of event-particles.
The required character of the abstractive sets which form event-particles would be secured if we could define them as having the property of being covered by any abstractive set which they cover.

For then any other abstractive set which an abstractive set of an event-particle covered, would be equal to it, and would therefore be a member of the same event-particle.