TO_LEFT
#define BOTH_LEFT (TO_LEFT + TO_LEFT)
#define IN_MIDDLE (TO_RIGHT + TO_LEFT)
base_side = TO_LEFT; /* to the left */
end_side = TO_LEFT; /* to the left */
#define BOTH_LEFT (TO_LEFT + TO_LEFT)
#define IN_MIDDLE (TO_RIGHT + TO_LEFT)
base_side = TO_LEFT; /* to the left */
end_side = TO_LEFT; /* to the left */