diff -r 029e2862bb4e -r b84ea52bfd8f slides/slides02.tex
--- a/slides/slides02.tex	Tue Nov 12 00:41:00 2019 +0000
+++ b/slides/slides02.tex	Tue Nov 12 10:47:27 2019 +0000
@@ -441,7 +441,7 @@
 \end{lstlisting}
 \end{onlyenv}\bigskip\bigskip\bigskip
  
-in the Scala code it is clear from the type I have to deal 
+in the Scala code it is clear from the type I that have to deal 
 with the \pcode{None}-case; no JavaDoc needed
   
 \end{frame}
@@ -574,9 +574,24 @@
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%     
 \begin{frame}[c,fragile]
-\frametitle{Recursion}
+\frametitle{Pattern Matching}
+
+\ldots on pairs:\bigskip
 
+\begin{lstlisting}[language=Scala, numbers=none, xleftmargin=-2mm]
+def fizz_buzz(n: Int) : String = 
+ (n % 3, n % 5) match {
+   case (0, 0) => "fizz buzz"
+   case (0, _) => "fizz"
+   case (_, 0) => "buzz"
+   case _ => n.toString  
+ }
+\end{lstlisting}
+\end{frame}
 
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%     
+\begin{frame}[c,fragile]
+\frametitle{Recursion}
 
 \begin{lstlisting}[language=Scala, numbers=none, xleftmargin=-2mm]
 def fib(n: Int) : Int = { 
@@ -646,11 +661,84 @@
   
   \begin{textblock}{14}(2,11.4)
   \large\bf{}Mind-Blowing Programming Languages:\\ 
-  \centering PHP
+  \centering PHP \textcolor{gray}{(7.0)}
   \end{textblock}
   \end{frame}
   %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%     
+
+\begin{frame}[c]
+\frametitle{Jumping Towers}
+
+\begin{center}
+\begin{tikzpicture}[scale=1.2]
+  \draw[line width=1mm,cap=round] (0,0) -- (5,0);
+  \draw[line width=1mm,cap=round] (0,1) -- (5,1);
+
+  \draw[line width=1mm,cap=round] (0,0) -- (0,1);
+  \node at (0.5,0.5) {\textbf{\Large 3}};
+
+  \draw[line width=1mm,cap=round] (1,0) -- (1,1);
+  \node at (1.5,0.5) {\textbf{\Large 4}};
+
+  \draw[line width=1mm,cap=round] (2,0) -- (2,1);
+  \node at (2.5,0.5) {\textbf{\Large 2}};
+
+  \draw[line width=1mm,cap=round] (3,0) -- (3,1);
+  \node at (3.5,0.5) {\textbf{\Large 0}};
+  
+  \draw[line width=1mm,cap=round] (4,0) -- (4,1);
+
+  \node at (4.5,0.5) {\textbf{\Large 1}};
+  
+  \draw[line width=1mm,cap=round] (5,0) -- (5,1);
+
+  \draw[->,line width=0.5mm,cap=round,out=90,in=90,relative] (0.5,1) to (1.5,1);
+  \draw[->,line width=0.5mm,cap=round,out=90,in=90,relative] (0.5,1) to (2.5,1);
+  \draw[->,line width=0.5mm,cap=round,out=90,in=90,relative] (0.5,1) to (3.5,1);
+
+  \draw[->,line width=0.5mm,cap=round,out=-90,in=-90,relative] (2.5,0) to (3.5,0);
+  \draw[->,line width=0.5mm,cap=round,out=-90,in=-90,relative] (2.5,0) to (4.5,0);
+
+  \draw[->,line width=0.5mm,cap=round,out=90,in=90,relative] (4.5,1) to (5.7,1);
+  \node at (5.7, 0.8) {End};
+\end{tikzpicture}
+\end{center}\bigskip
+
+
+shortest: 3 $\rightarrow$ 4 $\rightarrow$ End
+
+\end{frame}
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%     
+
+\begin{frame}[c]
+\frametitle{``Children'' / moves}
+
+\begin{center}
+  \begin{tikzpicture}
+    [grow=right,level distance=30mm,child anchor=north,line width=0.5mm]
+  \node {$[3,4,2,0,1]$}
+     child {node {$[0,1]$}}
+     child {node {$[2,0,1]$}
+        child {node {$[1]$} child [level distance=13mm] {node {End}}}
+        child {node {$[0,1]$}}
+     }
+     child {node {$[4,2,0,1]$\ldots}};
+\end{tikzpicture}
+\end{center}
+
+
+
+\end{frame}
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
 \end{document}