How to create an intersection symbol in LaTeX?

# How to create an intersection symbol in LaTeX?

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This article aims to show you the simplest and easiest way to write a degree symbol in LaTeX.

If you are working with sets or intervals you will definitely need to write the intersection symbol at some point. That’s why today you will learn how to write it in your LaTeX documents.

## Intersection Symbol

In mathematics, given two sets A and B, the intersection between both sets (or subset) is denoted by the symbols . Therefore the intersection of A and B will be defined as

$$A\cap B=\{x\,:\, x \in A \text{ or } x \in B\}$$


This denotes the common section between the two sets.

## Intersection Symbol in LaTeX

Now that we know how the formal definition looks in mathematics, it is time to learn how to insert this intersection character. To write this sign you use the command \cap, it takes no value as an argument and must be inside math mode.

It does not require extra packages since it is built-in. For example

\begin{document}
$$\left( A \cap B \right) \cap C$$
\end[document}


Gives the output

You may recall that it is similar to the union symbol command \cup, but instead of “backslash + cup”, it is “backslash + cap”.

It is possible to add superscripts or subscripts, depending on the context, for other notations used in set theory, for example,

\begin{document}
$$\cap_{i=1}^{n}X_{i}$$
\end[document}


Gives the output

## Big Intersection Symbol

Just like the big union symbol, there is a big intersection symbol. To write it you use the command \bigcap, for example

\begin{document}
$$\bigcap_{i=1}^{n}A_{i}$$
\end{document}


You can also write the limits with the intersection sing along with the limits, you can use the commands \bigcap and \limits, for example

\documentclass{article}
\begin{document}
\begin{center}
$$\bigcup\limits_{i=1}^{\infty}A_{i}$$
\end{center}
\end{document}


It is also pretty common to talk about the empty set in set theory involving intersections of two given sets. For example

\documentclass{article}
\begin{document}
$$A \cap \emptyset = \emptyset$$ %empty character
\end{document}


The intersection of any set with the empty set results in the empty set.

Sometimes LaTeX looks like Greek letters but don’t worry it only requires patience and more patience to master it, reading one greek letter at the time can help. Luckily now you know how to write this symbol in its two main forms in LaTeX.

I hope this article was helpful in guiding you in LaTeX, and as always keep writing in LaTeX.