Fixed tag.

Author: janpgit

intro.tex

@@ -2228,7 +2228,7 @@
 \end{itemize}
 \end{slide}
 
-The version that appeared in FreeBSD (\textrm{getopt\_long} is not part
+The version that appeared in FreeBSD (\texttt{getopt\_long} is not part
 of the standard), has the following properties:
 
 \begin{itemize}