Category:Definitions/Ordinals

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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