\begin{itemize}
\item [(a)] Surfaces, polyhedra
\item [(b)] Pontryagin surfaces, Pontryagin disk (sphere)
\item [(c)] 2-dimensional AR containing no disk
\item [(d)] Borsuk's hat
\item [(e)] Alexander horned sphere
\item [(f)] Bing dogbone space
\item [(g)] Other examples
\end{itemize}
