Complement in LaTeX (A')

Where it is used

A prime after a variable or set, a compact notation for the complement or Boolean negation of A.

Set theory courses often write A' for the complement U \setminus A, and some logic design books write A' instead of \overline{A} because it fits on one line and is easy to type. In math mode the apostrophe becomes a superscript \prime automatically, so A'' gives a double prime with correct spacing. The danger is ambiguity: A' also denotes derivatives, derived sets in topology, and dual spaces. Alternatives include A^c and A^{\complement}. Whichever you pick, define it once near the start of the document.

Minimal compilable example

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

\documentclass{article}
\begin{document}
Complement: $A'$

\[ (A \cup B)' = A' \cap B' \]
\end{document}

Related symbols

• De Morgan\overline{A \cdot B} = \overline{A} + \overline{B}
• Boolean NOT\overline{A}
• Boolean ORA + B
• Boolean ANDA \cdot B
• Contradiction (falsum, bottom)\bot
• Tautology (verum, top)\top

Frequently asked questions

How do I write Complement in LaTeX?

Type A' in math mode, for example $(A \cup B)' = A' \cap B'$. It works in plain LaTeX without loading any package.

Which package do I need for A'?

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

Can I use A' in text mode, or only in math mode?

Both. A' compiles in running text as well as inside $...$; in a formula keep it in math mode so it gets math fonts and spacing.