# In notation

In mathematics, the notation \(x \in X\) (where \(\in\) is written “\in” in LaTeX) means that \(X\) is a set and \(x\) is an element of that set.

# Examples

\(r \in \mathbb{R}\) means that \(r\) is a real number.

Parents:

In mathematics, the notation \(x \in X\) (where \(\in\) is written “\in” in LaTeX) means that \(X\) is a set and \(x\) is an element of that set.

\(r \in \mathbb{R}\) means that \(r\) is a real number.

Parents: