+#define POSN_STRING(posn) (Fnth (make_number (4), (posn)))
+
+/* If POSN_STRING is nil, event refers to buffer location. */
+
+#define POSN_INBUFFER_P(posn) (NILP (POSN_STRING (posn)))
+#define POSN_BUFFER_POSN(posn) (Fnth (make_number (5), (posn)))