Accordingly there are different types of extrinsic character of convergence which lead to the approximation to different types of intrinsic characters as limits.
We now pass to the investigation of possible connexions between abstractive sets.

One set may 'cover' another.

I define 'covering' as follows: An abstractive set p covers an abstractive set q when every member of p contains as its parts some members of q.

It is evident that if any event e contains as a part any member of the set q, then owing to the transitive property of extension every succeeding member of the small end of q is part of e.

In such a case I will say that the abstractive set q 'inheres in' the event e.