\end{verbatim}
For each subobject that can participate in cycles, we need to call the
-\cfunction{visit} function passed to the traversal method passing the
-subobject and the extra argument passed to the traversal method.
+\cfunction{visit} function, which is passed to the traversal method.
+The \cfunction{visit} function takes as arguments the subobject and
+the extra argument \var{arg} passed to the traversal method.
We also need to provide a method for clearing any subobjects that can
participate in cycles. We implement the method and reimplement the
\end{verbatim}
That's pretty much it. If we had written custom \member{tp_alloc} or
-\member{tp_free} slots, we'd need to modify then for cyclic-garbage
+\member{tp_free} slots, we'd need to modify them for cyclic-garbage
collection. Most extensions will use the versions automatically
provided.