Real numbers symbol (ℝ) in LaTeX

Real numbers symbol (ℝ)

Set theory

ℝ

LaTeX command

\mathbb{R}

reals

Use inside math mode: $\mathbb{R}$ — needs \usepackage{amssymb}

Blackboard bold letters denote the standard number sets. \mathbb comes from amssymb (or amsfonts) in LaTeX and is built into KaTeX and MathJax, so it works in Confluence math macros without setup.

All ways to write it

Command	Use	Package
`\mathbb{R}`	reals	amssymb
`\mathbb{N}`	naturals ℕ	amssymb
`\mathbb{Z}`	integers ℤ	amssymb
`\mathbb{Q}`	rationals ℚ	amssymb
`\mathbb{C}`	complex ℂ	amssymb
`\mathbb{R}^n`	n-dimensional real space	none

Commands marked with a package need that \usepackage line in a LaTeX document.

Example

f\colon \mathbb{R}^n \to \mathbb{R}, \quad f(x) = \|x\|^2

A real-valued function on n-dimensional space.

Questions

\mathbb is undefined — what do I load?

\usepackage{amssymb} in a LaTeX document. In KaTeX, MathJax, and Confluence math apps it is already available.

Related symbols

Element of ∈ \in
Subset ⊆ \subseteq
Expectation 𝔼 \mathbb{E}[X]

Using real numbers in Confluence

Confluence Cloud has no built-in LaTeX. With LaTeX Math for Confluence you add a math macro to any page, type \mathbb{R} and it renders inline or as a block, with a live preview while you edit. Every command on this page renders there without extra packages.