Less Than in LaTeX (<)

Where it is used

The less-than relation, asserting that the left quantity is strictly smaller than the right.

Typed directly in math mode, < becomes a relation with proper surrounding space, as in 0 < x < 1 or a strict inequality in an epsilon-delta proof. Do not use it as an angle bracket for inner products; that is \langle. In text mode with the old default font encoding, < may print an inverted exclamation mark, so write \textless or use math mode. Its non-strict form is \leq (or \le), and the negation is \not< or \nless. Web renderers like MathJax also accept \lt, which helps in HTML.

Also listed under: Inequalities & Order, Currency & Finance

Minimal compilable example

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

\documentclass{article}
\usepackage{amsmath}
\begin{document}
Less Than: $<$

\[ 0 < \varepsilon < \delta \implies |f(x) - L| < \varepsilon \]
\end{document}

Related symbols

• Greater Than>
• Less Than or Equal\leq
• Greater Than or Equal\geq
• Not Equal\neq
• Approximately Equal\approx
• Equivalent\equiv

Frequently asked questions

How do I write Less Than in LaTeX?

Type < in math mode, for example $0 < \varepsilon < \delta \implies |f(x) - L| < \varepsilon$. It works in plain LaTeX without loading any package.

Which package do I need for <?

None. < is part of standard LaTeX, so it compiles with nothing in the preamble but the document class.

Can I use < in text mode, or only in math mode?

Only in math mode. Outside $...$ LaTeX stops with "Missing $ inserted", so write $<$ in running text.