The Viewfinder algorithm is implemented in the MMT system and exposed within the jEdit-IDE, allowing us to realize the use case
stated in the introduction. A screenshot of Jane's theory of beautiful sets is given in Figure \ref{fig:use:source}; it
is based on the (basic higher-order logic) foundation of the Math-in-the-Middle\ednote{cite} library developed natively in MMT.
\begin{figure}[ht]\centering
\fbox{\includegraphics[width=0.6\textwidth]{beautysource}}
\fbox{\includegraphics[width=\textwidth]{results}}
\caption{A Theory of ``Beautiful Sets'' in MMT Surface Syntax and Results of the Viewfinder}\label{fig:use:source}
\end{figure}
Right-clicking anywhere within the theory allows Jane to select \cn{MMT} $\to$ \cn{Find\ Views\ to...} $\to$ \cn{MitM/smglom} (the main Math-in-the-Middle library), telling her (within less than one second) that two views have been found, the most promising of which points to the theory
\cn{matroid\_theory} (see Figure \ref{fig:use:target}) in the library.
\begin{figure}[ht]\centering
\fbox{\includegraphics[width=0.6\textwidth]{matroids}}
\caption{The Theory of Matroids in the MitM Library}\label{fig:use:target}
\end{figure}
\paragraph{} Using a different library as target, we can for example quickly write down a theory for a commutative binary operator (still using the Math-in-the-Middle foundation), allowing us to search e.g. the PVS Prelude library for any commutative operators, as in Figure \ref{fig:use:pvs}.
\begin{figure}[ht]\centering
\fbox{\includegraphics[width=\textwidth]{pvs}}
\caption{Searching for Commutative Operators in PVS}\label{fig:use:pvs}
\end{figure}