/* Return yx_uint16 coordinate one step from coordinate yx in direction dir. */
extern struct yx_uint16 mv_yx_in_dir(enum dir d, struct yx_uint16 yx);
/* Return yx_uint16 coordinate one step from coordinate yx in direction dir. */
extern struct yx_uint16 mv_yx_in_dir(enum dir d, struct yx_uint16 yx);