\section{Functions}
\label{sec:funcs}
The basic layout of an function in xml is as so:
\begin{Verbatim}[frame=single]
<Function operand="value of operand" type="type of function"/>
\end{Verbatim}
The value for the operand attribute must be a number. The value for the type attribue must be
one of the following:
\begin{itemize}
\item SubtractionFunction($number type$)
\item AdditionFunction($number type$)
\item MultiplicationFunction($number type$)
\item DivisionFunction($number type$)
\end{itemize}
This list can be exapanded by creating your own custom function objects that subclass the 
``SimpleFunctionObject'' class in the teuchos package and by creating your own custom
xml converter that sublcasses the SimpleFunctionXMLConverter class.


