#define IS_DRAWABLE(e) ((e) < EL_BLOCKED)
#define IS_NOT_DRAWABLE(e) ((e) >= EL_BLOCKED)
#define TAPE_IS_EMPTY(x) ((x).length == 0)
#define IS_DRAWABLE(e) ((e) < EL_BLOCKED)
#define IS_NOT_DRAWABLE(e) ((e) >= EL_BLOCKED)
#define TAPE_IS_EMPTY(x) ((x).length == 0)