\ref{bbi-fig-bbi-gui}
(the exact appearance of \bbi is system and \bbtk version dependent)
\footnote{If you compiled \bbtk without \wx then \bbi does not have a
-graphical interface but a simple prompt).
+graphical interface but a simple prompt}.
\begin{figure}[!ht]
\caption{\label{bbi-fig-bbi-gui}The black box interpreter interface}