How to write a power set such as 2^{a}. only the first bracket gets raised to the 2

Question

I just need this format for writing power sets properly but its not formating correctly

$2^{\{a\}}$ , perhaps, assuming you really want visible braces. — Steven B. Segletes, Oct 08 '20 at 02:42
Welcome to TeX.SE. It's really helpful if you provide a minimal working example that shows what you have so far. 2^{a} would not yield braces. One way that would give the output you showed is 2^\{a\}, which is fixed the way that @ StevenB.Segletes suggests. — Teepeemm, Oct 08 '20 at 02:57
There is also \lbrace and \rbrace, more typing but easier to read. — John Kormylo, Oct 08 '20 at 12:50

score 1 · Answer 1 · answered Oct 13 '20 at 01:06

It's not clear what you were trying to do.

The usual advice for TeX is to write base^{exponent}, putting braces around the exponent. Everyone fairly quickly discovers that you can leave off the braces if the exponent is a single token (they also discover other times you can leave off the braces that I won't talk about). And as soon as someone needs to type {, they find out they should precede it with a backslash.

This leads us to what you probably tried: $2^\{a\}$ . The problem is that the ^ is followed by three tokens: {, a, and }. This means that the ^ only exponentiates the first token that it finds, leading to your output. But if you want to exponentiate more than one token, you need to enclose them in { and }. Otherwise, you would be expecting TeX to discover when the exponentiation should end. This leads you to the commented suggestion: $2^{\{a\}}$ .

\documentclass{article}
\begin{document}
 $ 2^a \quad 2^{a} \quad 2^\{a\} \quad 2^{\{a\}} $
\end{document}

How to write a power set such as 2^{a}. only the first bracket gets raised to the 2

1 Answers1