Empty Set (Variant) in LaTeX (\varnothing)

Where it is used

Variant empty-set symbol: a round circle with a diagonal slash, the set with no elements.

\varnothing and \emptyset mean the same thing, the empty set, but look different: \emptyset in Computer Modern is a narrow, tall zero with a slash, while \varnothing is a round circle with a slash that many mathematicians prefer. Use one consistently, for example A \cap B = \varnothing for disjoint sets. It is not the Greek letter \phi or \varphi, and not the Scandinavian letter \O, so avoid those as substitutes. Some authors redefine \emptyset to \varnothing in the preamble so every occurrence switches at once.

Also listed under: Geometry

Minimal compilable example

Paste this into an empty .tex file and compile it with pdfLaTeX, XeLaTeX or LuaLaTeX.

\documentclass{article}
\usepackage{amssymb,amsmath}
\begin{document}
Empty Set (Variant): $\varnothing$

\[ A \cap B = \varnothing \implies |A \cup B| = |A| + |B| \]
\end{document}

Related symbols

• Element Of\in
• Empty Set\emptyset
• Not Element Of\notin
• Contains\ni
• Subset\subset
• Subset or Equal\subseteq

Frequently asked questions

How do I write Empty Set (Variant) in LaTeX?

Type \varnothing in math mode, for example $A \cap B = \varnothing \implies |A \cup B| = |A| + |B|$. Load amssymb first with \usepackage{amssymb}.

Which package do I need for \varnothing?

\varnothing needs amssymb: add \usepackage{amssymb} to your preamble before the document starts.

Can I use \varnothing in text mode, or only in math mode?

Only in math mode. Outside $...$ LaTeX stops with "Missing $ inserted", so write $\varnothing$ in running text. If you only need the glyph in text, paste the Unicode character ∅ instead (with XeLaTeX or LuaLaTeX and a font that has it).