Category:Definitions/Ordinals

This category contains definitions related to Ordinals.
Related results can be found in Category:Ordinals.

Let $A$ be a set.

Then $A$ is an ordinal if and only if $A$ is:

transitive

epsilon-connected, that is:

$\forall x, y \in A: x \ne y \implies x \in y \lor y \in x$

well-founded