Each of these events occupies its own aggregate of event-particles.

These aggregates will have a common portion, namely the class of event-particle lying in all of them.

This class of event-particles is what I call the 'station' of the event-particle P in the duration d.

This is the station in the character of a locus.

A station can also be defined in the character of an abstractive element.
Let the property {sigma} be the name of the property which an abstractive set possesses when (i) each of its events is cogredient with the duration d and (ii) the event-particle P lies in each of its events.
Then the group of {sigma}-primes, where {sigma} has this meaning, is an abstractive element and is the station of P in d as an abstractive element.