Definition:Left Normal Element of Relation

Definition

Let $A$ be a class.

Let $\RR$ be a relation on $A$.

An element $x$ of $A$ is left normal with respect to $\RR$ if and only if:

$\forall y \in A: \map \RR {x, y}$ holds.

Sources

• 2010: Raymond M. Smullyan and Melvin Fitting: Set Theory and the Continuum Problem (revised ed.) ... (previous) ... (next): Chapter $3$: The Natural Numbers: $\S 4$ A double induction principle and its applications: Theorem $4.3$