# Definition:Set-Like Relation

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## Definition

Let $\RR$ be a relation.

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Let $A$ be a class.

Then $\RR$ is **set-like** on $A$ if and only if:

- For all $x \in A$, $\set {y \in A: y \mathrel \RR x}$ is a set.

## Sources

- 1980: Kenneth Kunen:
*Set Theory: An Introduction to Independence Proofs*: Definition $\text {III}.5.2$