Not Subset in LaTeX (\not\subset)

Where it is used

Slashed subset sign: the left set is not a subset of the right set.

\not\subset overlays a slash on \subset using the generic \not prefix. The result is acceptable, though the slash is sometimes off-center; the dedicated glyphs \nsubseteq (not a subset or equal) and \nsubset in some symbol packages look better. Since \subset itself is ambiguous between proper and non-strict inclusion, \nsubseteq is often the clearer negation. Example: \mathbb{Q} \not\subset \mathbb{Z}, because 1/2 is rational but not an integer. Keep \not directly before the relation, with no space or braces, so it combines correctly.

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}
Not Subset: $\not\subset$

\[ \mathbb{Q} \not\subset \mathbb{Z} \text{ since } \tfrac{1}{2} \notin \mathbb{Z} \]
\end{document}

Related symbols

• Proper Subset\subsetneq
• Subset or Equal\subseteq
• Superset\supset
• Subset\subset
• Superset or Equal\supseteq
• Contains\ni

Frequently asked questions

How do I write Not Subset in LaTeX?

Type \not\subset in math mode, for example $\mathbb{Q} \not\subset \mathbb{Z} \text{ since } \tfrac{1}{2} \notin \mathbb{Z}$. It works in plain LaTeX without loading any package.

Which package do I need for \not\subset?

None. \not\subset is part of standard LaTeX, so it compiles with nothing in the preamble but the document class.

Can I use \not\subset in text mode, or only in math mode?

Only in math mode. Outside $...$ LaTeX stops with "Missing $ inserted", so write $\not\subset$ 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).