# How to get lower-case letters in a page header

In latex when we write section include the chapter, on the top of pages it write as a capital letter, for example

\section{Solution in R^{n}}, on the top write SOLUTION IN R^N, my question is, who we control it especially I want to wrote " R^n " instead " R^N "

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Check this answer tex.stackexchange.com/a/4761/23688 –  mreq Jan 3 '13 at 9:36
BTW, your code \section{Solution in R^{n}} is wrong (Missing $inserted). Perhaps it must be \section{Solution in$R^{n}$} ? – Fran Jan 3 '13 at 9:43 dear Fran, even with '$ R^{n} $' not work, also i try to use the Petr Marek, but its another things, i need just how i write the section title i get the same things in the top of the page – Mathcal Jan 3 '13 at 9:55 By top of the page, do you mean headers? If so are you using fancyhdr? – Harish Kumar Jan 3 '13 at 13:51 ## 2 Answers Try this: \documentclass{book} \usepackage{lipsum} \begin{document} \tableofcontents \chapter{Lipsum} \section{S\lowercase{olution in}$R^{\lowercase{n}}$} \lipsum[1-15] \end{document}  - This is not a general solution, but for this particular example, the following will work. Define the command \Rn at the preamble as: \newcommand{\Rn}{$R^n$}  and use it when required in your document as \Rn{}, except at sections or chapters, where you have to \protect it to prevent the uppercase conversion: \section{Solution in \protect\Rn}  This is a MWE: \documentclass{book} \usepackage{lipsum} \def\Rn{$R^{n}\$}
\begin{document}
\tableofcontents
\chapter{Lipsum}
\section{Solution in \protect\Rn{}}
\lipsum[1-15]
\end{document}


And these are some exceprts of the resulting pdf, showing the relevant parts: