Probably the most interesting effect achieved by Beamer is
*overlays*, which gives the appearance of incremental exposure of a
given slide.

Achieving the overlay effect in Beamer is quite simple—just insert
a `\pause`

command anywhere you want to pause the display.

For instance, to expose an itemized list one-item-at-a-time, do:

\documentclass{beamer} \usetheme{default} \begin{document} \begin{frame}{Outline of the talk} \begin{itemize} \item Introduction \pause \item Statement of the main theorem \pause \item Technical lemmata \pause \item Proof of the main theorem \pause \item Conclusions \end{itemize} \end{frame} \end{document}

When this file is compiled into the pdf format and displayed with a pdf viewer, such as the Acrobat Reader, the items are exposed one-at-a-time as you page forward through the document in the usual way.

The use of the `\pause`

command is not restricted to itemized
lists; you may use it anywhere in a slide. For example:

\documentclass{beamer} \usetheme{Malmoe} \begin{document} \begin{frame}{Fermat's Last Theorem} In this talk I will give a very elementary proof of the theorem. I am surprised that no one else has thought of this before. \medskip \pause Fermat's Last Theorem says that the equation \[ x^2 + y^2 = z^2 \] has no solution in the set of natural numbers. \medskip \pause This is not true. After a lengthy calculation on the department's Linux machines, I have verified that within the numerical accuracy of the Pentium-4 processor, we have: \[ 5000^2 + 12000^2 = 13000^2 \] \end{frame} \end{document}

A pdf viewer will expose the resulting file one paragraph at a time. The fully exposed slide looks like this: