\begin{frame}
  \frametitle{Unified Modelling Language}
  
  \begin{goal}{}
    UML = Unified Modeling Language
  \end{goal}
  \bigskip
  
  \begin{exampleblock}{Example schema as UML class diagram}
    \begin{center}
    \begin{tikzpicture}
    \umlclass{customer}{ 
      +id \\
      +name \\
      +street \\
      +city 
      }{ 
      } 
    \umlclass[x=7]{account}{ 
      +account-number \\
      +balance
      }{ 
      } 
    \umlassoc[arg1=1..1,pos1=0.1,arg2=0..*,pos2=.9,name=assoc]{customer}{account} 
    \node [ao=assoc-1,xshift=-3mm] {deposits $\triangleright$};
    \node [bo=assoc-1,xshift=-3mm] {$\triangleleft$ depositor$\quad$};
    \end{tikzpicture} 
    \end{center}
  \end{exampleblock}
  \bigskip
  \pause
  
  \begin{itemize}
    \item UML diagrams are similar to ER diagrams\\
          \remark{However, there are important differences!}
  \end{itemize}
\end{frame}