\begin{frame}
  \frametitle{Component Extensions}
  
  Extend via extra \emph{filter nodes}
  
  \begin{center}
  \begin{tikzpicture}
    [ nd/.style={circle, minimum size=9mm, very thick, draw=blue!50!black!50, top color=white, bottom color=blue!50!black!20,font=\scriptsize}
    , nd2/.style={circle, minimum size=9mm, very thick, draw=red!50!black!50, top color=white, bottom color=red!50!black!20,font=\scriptsize}
    , nd3/.style={circle, minimum size=6mm, very thick, draw=green!50!black!50, top color=white, bottom color=green!50!black!20,font=\scriptsize}
    , nd4/.style={circle, minimum size=6mm, very thick, draw=purple!50!black!50, top color=purple!50!white!50, bottom color=purple!50,font=\scriptsize}
    , attr/.style={rectangle, minimum size=4mm, node distance=6mm, very thick, draw=black!50, top color=white, bottom color=black!20,font=\scriptsize}
    , inh/.style={attr}
    , syn/.style={attr}
    , leftfirst/.style={xshift=-4mm}
    , rightfirst/.style={xshift=4mm}
    , arr/.style={->,dashed, very thick}
    ]
    \node[nd2](n1){}
      [sibling distance=40mm]
      child {
        node[nd4](n2){}
          child {
            node[nd2](n3){}
              child {
                node{}
              }
              child {
                node{}
              }
          }
      }
      child {
        node{}
      };
  
  \node[inh,leftfirst](a11) [left of=n1] {};
  \node[syn,rightfirst](a12) [right of=n1] {};
  \node[syn] (n2syn2)(a13) [right of=a12] {};

  \node[inh,leftfirst](a21) [left of=n2] {};
  \node[syn,rightfirst](a22) [right of=n2] {};
  \node[syn] (n2syn2)(a23) [right of=a22] {};
  
  \node[inh,leftfirst](a31) [left of=n3] {};
  \node[syn,rightfirst](a32) [right of=n3] {};
  \node[syn] (n2syn2)(a33) [right of=a32] {};
  \end{tikzpicture}
  \end{center}
\end{frame}

\begin{frame}
  \frametitle{Example: let-bound polymorphism}
  
  \begin{center}
  \begin{tikzpicture}
    [ nd/.style={circle, minimum size=9mm, very thick, draw=blue!50!black!50, top color=white, bottom color=blue!50!black!20,font=\scriptsize}
    , nd2/.style={circle, minimum size=9mm, very thick, draw=red!50!black!50, top color=white, bottom color=red!50!black!20,font=\scriptsize}
    , nd3/.style={circle, minimum size=6mm, very thick, draw=green!50!black!50, top color=white, bottom color=green!50!black!20,font=\scriptsize}
    , nd4/.style={circle, minimum size=6mm, very thick, draw=purple!50!black!50, top color=purple!50!white!50, bottom color=purple!50,font=\scriptsize}
    , tr/.style={isosceles triangle,rotate=90, minimum size=12mm, very thick, draw=blue!50!black!50, top color=white, bottom color=blue!50!black!20,font=\footnotesize}
    , attr/.style={rectangle, minimum size=4mm, node distance=6mm, very thick, draw=black!50, top color=white, bottom color=black!20,font=\scriptsize}
    , inh/.style={attr}
    , syn/.style={attr}
    , leftfirst/.style={xshift=-4mm}
    , rightfirst/.style={xshift=4mm}
    , arr/.style={->,dashed, very thick}
    ]
  \node[nd4](e1){}
    child {
      node[nd2](n1){|sc|}
        child {
          node[nd2](n2){|split|}
            [sibling distance=40mm]
            child {
              node[tr](n3){|decls|}
            }
            child {
              node[nd4](e2){}
                child {
                  node[tr](n4){|body|}
                }
            }
        }
    };
  \pause
  \node[nd, right of=e1, xshift=30mm](x1){|let|};
  \pause
  \node[nd3,left of=x1, xshift=6mm](e3){};
  \node[nd3,below of=x1, yshift=6mm](e4){};
  \draw[-,dashed](e1) to (e3);
  \draw[-,dashed](e2) to (e4);
  \end{tikzpicture}
  \end{center}
\end{frame}

\begin{frame}
  \frametitle{Example: let-bound polymorphism - code}
  
  \begin{code}
  sem_Expr_Let ds b
    =  sem :: Expr
         lhs.nmTree  =  loc.semTop $ sem_Name_Scope $
                        sem_Name_Split decls.nmTree $
                        loc.semBody body.nmTree
       
         loc.semTop t  =  
           sem :: Name Ty
             child body :: Name Ty = t
             loc.parentEnv = lhs.finEnv
       
         loc.semBody t  =
           sem :: Name Ty
             child body :: Name Ty = t
             body.finEnv = generalize  lhs.finEnv
                                       loc.parentEnv
  \end{code}
\end{frame}

\begin{frame}
  \frametitle{AG convenience}
  
  \begin{itemize}
  \item Override one or two attributes with filter nodes
  \item Copy rules take care of the rest
  \end{itemize}
\end{frame}

\begin{frame}
  \frametitle{Limitations}
  
  \begin{center}
  \begin{tikzpicture}
    [ nd/.style={circle, minimum size=9mm, very thick, draw=blue!50!black!50, top color=white, bottom color=blue!50!black!20,font=\scriptsize}
    , nd2/.style={circle, minimum size=9mm, very thick, draw=red!50!black!50, top color=white, bottom color=red!50!black!20,font=\scriptsize}
    , nd3/.style={circle, minimum size=6mm, very thick, draw=green!50!black!50, top color=white, bottom color=green!50!black!20,font=\scriptsize}
    , attr/.style={rectangle, minimum size=4mm, node distance=6mm, very thick, draw=black!50, top color=white, bottom color=black!20,font=\scriptsize}
    , inh/.style={attr}
    , syn/.style={attr}
    , leftfirst/.style={xshift=-4mm}
    , rightfirst/.style={xshift=4mm}
    , arr/.style={->,dashed, very thick}
    ]
  \node[nd](n1){}
    child {
      node[nd](n2){}
        child {
          node[nd](n3){}
            child {
              node[nd](n4){}
                child {
                  node[nd](n5){}
                }
            }
        }
    };

  \node[nd2, right of=n1, xshift=40mm, yshift=5mm](r1){}
    child {
      node[nd2](r2){}
        child {
          node[nd2](r3){}
            child {
              node[nd2](r4){}
                child {
                  node[nd2](r5){}
                }
            }
        }
    };
  
  \node[nd3, right of=n1, xshift=-4mm](e1){};
  \node[nd3, right of=n2, xshift=-4mm](e2){};
  \node[nd3, right of=n3, xshift=-4mm](e3){};
  \node[nd3, right of=n4, xshift=-4mm](e4){};
  \node[nd3, right of=n5, xshift=-4mm](e5){};
  
  \draw[-](e1) to (r1);
  \draw[-](e2) to (r2);
  \draw[-](e3) to (r3);
  \draw[-](e4) to (r4);
  \draw[-](e5) to (r5);

  \end{tikzpicture}
  \end{center}
\end{frame}