presentation: correction to for syntax, add predicated typing for for!

presentation/main.tex

@@ -49,8 +49,8 @@
 % show slide numbers
 \setbeamertemplate{footline}[frame number]
 
-% \setbeameroption{hide notes}
-\setbeameroption{show notes}
+\setbeameroption{hide notes}
+% \setbeameroption{show notes}
 % \setbeameroption{show only notes}
 
 \begin{document}
@@ -1203,7 +1203,7 @@ let
              of Some item' => for rest (insert $\iota$ item') expr
               | None => for rest $\iota$ expr
 in
-  for <var> <collection> default (fn <var> => <expr>)
+  for <collection> default (fn <var> => <expr>)
 end
   \end{lstlisting}
 \end{frame}
@@ -1237,6 +1237,17 @@ end
 \end{frame}
 
 
+\begin{frame}{Iteration: big payoff!}
+  \begin{align*}
+    \tt{for} :: \forall \gamma . \forall iota .&\\
+      &(\tt{item} :: \gamma \bs \tt{item}_\gamma) .\\
+      &(\tt{item} :: \iota \bs \tt{item}_\iota) .\\
+      &(\tt{next} ::_i \gamma \arrow (\tt{item}_\gamma * \gamma) \tt{ option} \bs \tt{next}_\gamma) .\\
+      &(\tt{insert} ::_i \iota \arrow \tt{item}_\iota \arrow \iota) .\\
+      &\gamma \arrow \iota \arrow (\tt{item}_\gamma \arrow \tt{item}_\iota) \arrow \iota
+  \end{align*}
+\end{frame}
+
 \begin{frame}{}
   \begin{center}
     \Large Thank you!