\begin{frame}[t]
  \frametitle{Cardinality Limits: Alternative Notations}

  \begin{alertblock}{}
    There are many different notations for ER models.
  \end{alertblock}
  \bigskip\pause
  
  For example:
  \begin{center}
  \begin{tikzpicture}[every edge/.style={link},node distance=12mm,>=triangle 45]
    \begin{scope}
      \node[relationship] (R) {R};
      \node (l) [left of=R,entity,minimum size=4mm] {A}; \draw (R) -- (l); 
      \node (r) [right of=R,entity,minimum size=4mm] {B}; \draw (R) -- (r);
    
      \node at (3.35cm,0cm) {is alternative for};
      
      \begin{scope}[xshift=7cm,node distance=15mm]
        \node[relationship] (R) {R};
        \node (l) [left of=R,entity,minimum size=4mm] {A}; \draw (R) -- node[above,pos=.5] {$0\sldots *$} (l); 
        \node (r) [right of=R,entity,minimum size=4mm] {B}; \draw (R) -- node[above,pos=.5] {$0\sldots *$} (r);
      \end{scope}
    \end{scope}
  \end{tikzpicture}
  \medskip
  
  \begin{tikzpicture}[every edge/.style={link},node distance=12mm,>=triangle 45]
    \begin{scope}
      \node[relationship] (R) {R};
      \node (l) [left of=R,entity,minimum size=4mm] {A}; \draw [->] (R) -- (l); 
      \node (r) [right of=R,entity,minimum size=4mm] {B}; \draw (R) -- (r);
    
      \node at (3.35cm,0cm) {is alternative for};
      
      \begin{scope}[xshift=7cm,node distance=15mm]
        \node[relationship] (R) {R};
        \node (l) [left of=R,entity,minimum size=4mm] {A}; \draw (R) -- node[above,pos=.5] {$0\sldots 1$} (l); 
        \node (r) [right of=R,entity,minimum size=4mm] {B}; \draw (R) -- node[above,pos=.5] {$0\sldots *$} (r);
      \end{scope}
    \end{scope}
  \end{tikzpicture}
  \medskip
  
  \begin{tikzpicture}[every edge/.style={link},node distance=12mm,>=triangle 45]
    \begin{scope}
      \node[relationship] (R) {R};
      \node (l) [left of=R,entity,minimum size=4mm] {A}; \draw [-] (R) -- (l); 
      \node (r) [right of=R,entity,minimum size=4mm] {B}; \draw [->] (R) -- (r);
    
      \node at (3.35cm,0cm) {is alternative for};
      
      \begin{scope}[xshift=7cm,node distance=15mm]
        \node[relationship] (R) {R};
        \node (l) [left of=R,entity,minimum size=4mm] {A}; \draw (R) -- node[above,pos=.5] {$0\sldots *$} (l); 
        \node (r) [right of=R,entity,minimum size=4mm] {B}; \draw (R) -- node[above,pos=.5] {$0\sldots 1$} (r);
      \end{scope}
    \end{scope}
  \end{tikzpicture}
  \medskip
  
  \begin{tikzpicture}[every edge/.style={link},node distance=12mm,>=triangle 45]
    \begin{scope}
      \node[relationship] (R) {R};
      \node (l) [left of=R,entity,minimum size=4mm] {A}; \draw [->] (R) -- (l); 
      \node (r) [right of=R,entity,minimum size=4mm] {B}; \draw [->] (R) -- (r);
    
      \node at (3.35cm,0cm) {is alternative for};
      
      \begin{scope}[xshift=7cm,node distance=15mm]
        \node[relationship] (R) {R};
        \node (l) [left of=R,entity,minimum size=4mm] {A}; \draw (R) -- node[above,pos=.5] {$0\sldots1$} (l); 
        \node (r) [right of=R,entity,minimum size=4mm] {B}; \draw (R) -- node[above,pos=.5] {$0\sldots1$} (r);
      \end{scope}
    \end{scope}
  \end{tikzpicture}
  \end{center}
\end{frame}