\begin{frame}
  \frametitle{ER Models vs. UML Class Diagrams}

  \begin{goal}{Non-Binary Relationships}
  \begin{minipage}{.49\textwidth}
    \begin{center}
    \scalebox{.92}{\small
    \begin{tikzpicture}[every edge/.style={link},node distance=18mm,>=triangle 45,inner sep=.5mm]
      \begin{scope}
        \node[relationship] (R) {R};
        \node (l) [left of=R,entity] {E1}; \draw (R) -- (l); 
        \node (r) [right of=R,entity] {E2}; \draw (R) -- (r);
        \node (t) [above of=R,entity] {E3}; \draw (R) -- (t);
      \end{scope}
    \end{tikzpicture}
    }
    \end{center}
  \end{minipage}
  \begin{minipage}{.49\textwidth}
    \begin{center}
    \quad\quad\begin{tikzpicture}[nodes={xscale=.8}]
    \umlclass[width=5mm]{E1}{ 
      \ldots
    }{} 
    \umlclass[x=3.5cm,width=5mm]{E2}{ 
      \ldots
    }{} 
    \umlclass[x=1.75cm,y=2cm,width=5mm]{E3}{ 
      \ldots
    }{} 
    \umlNarynode[x=1.75cm, name=naryassoc, below]{R}

    \umlassoc{E1}{naryassoc} 
    \umlassoc{E2}{naryassoc} 
    \umlassoc{E3}{naryassoc} 
    \end{tikzpicture} 
    \end{center}
  \end{minipage}
  \end{goal}
  \begin{itemize}
    \item Non-binary relationship sets are drawn using a diamond.
  \end{itemize}
\end{frame}