+#define DBG_MEM 0
+#define DBG_MEM_START 1
+
+#if DBG_MEM
+
+#include <assert.h>
+extern int dbg_move_depth;
+#define MDBG_DUMP 1
+#define MDBG_OFFSET(a) ((int) ((uint8_t *) (a) - ao_lisp_pool))
+
+extern int dbg_mem;
+
+#define MDBG_DO(a) a
+#define MDBG_MOVE(...) do { if (dbg_mem) { int d; for (d = 0; d < dbg_move_depth; d++) printf (" "); printf(__VA_ARGS__); } } while (0)
+#define MDBG_MORE(...) do { if (dbg_mem) printf(__VA_ARGS__); } while (0)
+#define MDBG_MOVE_IN() (dbg_move_depth++)
+#define MDBG_MOVE_OUT() (assert(--dbg_move_depth >= 0))
+
+#else
+
+#define MDBG_DO(a)
+#define MDBG_MOVE(...)
+#define MDBG_MORE(...)
+#define MDBG_MOVE_IN()
+#define MDBG_MOVE_OUT()
+
+#endif
+