+#if (defined(GCap) || defined(GCgn))
+typedef struct clos /* a queue of ex-RBHs (needed for gen GC only) */
+{
+ struct clos *prev, *next;
+ P_ closure;
+} *closq;
+
+#define CLOS_CLOSURE(clos) (clos->closure)
+#define CLOS_PREV(clos) (clos->prev)
+#define CLOS_NEXT(clos) (clos->next)
+#endif
+