Definition:Diagonal Relation/Class Theory

Definition
Let $V$ be a basic universe.

The diagonal relation on $V$ is the relation $\Delta_V$ on $V$ defined as:


 * $\Delta_V = \set {\tuple {x, x}: x \in V}$

Alternatively:


 * $\Delta_V = \set {\tuple {x, y}: x, y \in V: x = y}$

Also see

 * Definition:Equals
 * Diagonal Relation is Equivalence


 * Definition:Identity Mapping