*25. THE UNIVERSAL RELATION, THE NULL RELATION, AND THE EXISTENCE OF RELATIONS.
Project Gutenberg EPUB3 edition
Whitehead, Alfred North and Russell, Bertrand
Summary of *25.
This number contains the analogues, for relations, of the definitions and propositions of *24. Proofs will not be given, as they proceed precisely as in *24.
The universal relation, denoted by , is the relation which holds between any two terms whatever of the appropriate types, whatever these may be in the given context. The null relation, , is the relation which does not hold between any pair of terms whatever, its type being fixed by the types of the terms concerning which the denial that it holds is significant. A relation is said to exist when there is at least one pair of terms between which it holds; " exists" is written "."
The propositions of this number are much less often referred to than those of *24, but for the sake of uniformity we have given the analogues of all propositions in *24, with the same numeration (except for the integral part).
All the remarks made in *24 apply, mutatis mutandis, in the present number.
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