replace brackets and quotes with em dash and i.e.

doc/chapter/3ui.tex

@@ -60,7 +60,7 @@ The possible inputs are listed in table~\ref{table:keys}.
         \hline
         Key & Action \\\hline\hline
         Left arrow key & Perform one forward step of the algorithm. \\\hline
-        Right arrow key & Perform one backward step (\enquote{undo one step}) of the algorithm. \\\hline
+        Right arrow key & Perform one backward step---i.e.\ undo one step of the algorithm. \\\hline
         P & Pause/unpause the automatic execution. Initially paused. \\\hline
         D & Print a debug table to standard out. \\\hline
     \end{longtable}