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Aleph-0

The Set Theory symbol for a Set having the same Cardinal Number as the ``small'' Infinite Set of Integers. The Algebraic Numbers also belong to $\aleph_0$. Rather surprising properties satisfied by $\aleph_0$ include

\begin{displaymath}
{\aleph_0}^r=\aleph_0
\end{displaymath} (1)


\begin{displaymath}
r{\aleph_0}=\aleph_0
\end{displaymath} (2)


\begin{displaymath}
{\aleph_0}+f=\aleph_0,
\end{displaymath} (3)

where $f$ is any Finite Set. However,
\begin{displaymath}
{\aleph_0}^{\aleph_0}=C,
\end{displaymath} (4)

where $C$ is the Continuum.

See also Aleph-1, Cardinal Number, Continuum, Continuum Hypothesis, Countably Infinite Set, Finite, Infinite, Transfinite Number, Uncountably Infinite Set




© 1996-9 Eric W. Weisstein
1999-05-25