Jelaskan Contoh: dari Bilangan ordinal

Himpunan bilangan ordinal kurang dari 3 adalah 3 = , bilangan ordinal terkecil tidak kurang dari 3.

Himpunan bilangan ordinal terhingga adalah tak terhingga, bilangan ordinal tak terhingga terkecil: ω.

Himpunan bilangan ordinal terhitung adalah tak terhitung, bilangan ordinal tak terhitung terkecil: ω1.

Cantor, G., (1897), Beitrage zur Begrundung der transfiniten Mengenlehre. II (tr.: Contributions to the Founding of the Theory of Transfinite Numbers II), Mathematische Annalen 49, 207-246 English translation.

Conway, J. H. and Guy, R. K. "Cantor's Ordinal Numbers." In The Book of Numbers. New York: Springer-Verlag, pp. 266–267 and 274, 1996.

Dauben, Joseph Warren, (1990), Georg Cantor: his mathematics and philosophy of the infinite. Chapter 5: The Mathematics of Cantor's Grundlagen. ISBN 0-691-02447-2

See Ch. 6, "Ordinal and cardinal numbers"

Kanamori, A., Set Theory from Cantor to Cohen, to appear in: Andrew Irvine and John H. Woods (editors), The Handbook of the Philosophy of Science, volume 4, Mathematics, Cambridge University Press.

Reprinted 2002, Dover. ISBN 0-486-42079-5

Sierpiński, W. (1965). Cardinal and Ordinal Numbers (2nd ed.). Warszawa: Państwowe Wydawnictwo Naukowe. Also defines ordinal operations in terms of the Cantor Normal Form.

Suppes, P. (1960), Axiomatic Set Theory, D.Van Nostrand Company Inc., ISBN 0-486-61630-4

- English translation of .