--- a/progs/matcher/re1.sc	Fri Oct 10 10:18:05 2025 +0100
+++ b/progs/matcher/re1.sc	Fri Oct 10 12:26:29 2025 +0100
@@ -222,6 +222,7 @@
 
 @main
 def test4() = {
+  val r2 = SEQ(SEQ(CHAR('x'), CHAR('y')), CHAR('z'))
   println(pp(r2))
   println(pp(ders("x".toList, r2)))
   println(pp(ders("xy".toList, r2)))

Binary file slides/slides02.pdf has changed

--- a/slides/slides02.tex	Fri Oct 10 10:18:05 2025 +0100
+++ b/slides/slides02.tex	Fri Oct 10 12:26:29 2025 +0100
@@ -68,7 +68,8 @@
 
   \begin{textblock}{5}(12,3)
   \includegraphics[scale=0.35]{qr01}\\
-  %%\small Wifi: IET-Guest
+  \small{}Wifi: Lincoln's Inn\\
+  \small{}Pwd: 0207\,4051\,393
   \end{textblock} 
 \end{frame}
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%     
@@ -89,7 +90,7 @@
 \begin{center}
 \begin{tabular}{c}
 \includegraphics[scale=0.024]{awards.jpeg}\\
-\small I try my best, but \ldots
+\small I try my best, but \ldots\ldots\ldots\ldots\textcolor{gray}{server, venue}
 \end{tabular} 
 \end{center} 
 \mbox{}
@@ -112,20 +113,20 @@
 \end{center}\small
 
 
-\begin{tabular}{@{}l}
+\begin{tabular}{@{}l@{\hspace{18mm}}l}
 KEYWORD: \\
 \hspace{5mm}{if}, {then}, {else},\ldots\\ 
 WHITESPACE:\\
 \hspace{5mm}{" "}, {$\backslash$n}, {$\backslash$r}\\ 
 IDENTIFIER:\\
-\hspace{5mm}LETTER $\cdot$ (LETTER + DIGIT + {\_})$^*$\\ 
-NUM:\\
-\hspace{5mm}(NONZERODIGIT $\cdot$ DIGIT$^*$) + {0}\\
+\hspace{5mm}LETTER $\cdot$ (LETTER + DIGIT + {\_})$^*$ & LETTER: [a-zA-Z]\\ 
+NUM: & DIGIT: [0-9]\\
+\hspace{5mm}(NONZERODIGIT $\cdot$ DIGIT$^*$) + {0} & NONZERODIGIT: [1-9]\\
 NUMBER:\\
 \hspace{5mm}NUM +  (\texttt{"-"} $\cdot$ NUM)\\
 OP:\\
-\hspace{5mm}+, -, *, \%, <, =<,\ldots\\
-COMMENTS:\\
+\hspace{5mm}=, :=, +, -, *, \%, <, =<,\ldots\\
+COMMENT:\\
 \hspace{5mm}{$\slash$*} $\cdot$ $\sim$(ALL$^*$ $\cdot$ (*$\slash$) $\cdot$ ALL$^*$) $\cdot$ {*$\slash$}
 \end{tabular}