Definition:Cardinality/Infinite

Definition
Let $S$ be an infinite set.

The cardinality $\card S$ of $S$ can be indicated as:
 * $\card S = \infty$

However, it needs to be noted that this just means that the cardinality of $S$ cannot be assigned a number $n \in \N$.

It means that $\card S$ is at least $\aleph_0$ (aleph null).

Also see

 * Definition:Cardinal


 * Definition:Set Equivalence


 * Definition:Aleph Number ($\aleph_0, \aleph_1, \ldots$)
 * Definition:Beth Number ($\beth_0, \beth_1, \ldots$)