#define P_CORR      0x01
  #define P_SUB       0x02
  #define P_INS       0x04
  #define P_DEL       0x08
  #define P_MRG       0x10
  #define P_SPL       0x20
  
  typedef struct PATH_SET_struct {
      void *a_ptr,         /* pointer to A arc's data */
           *b_ptr;         /* pointer to B arc's data */
      char eval;           /* flag to designated the pair as Corr, Ins, Del, Sub */
  } PATH_SET;
  
  
  #define PA_NONE           0x0000
  #define PA_CHAR_ALIGN     0x0001
  #define PA_CASE_SENSE     0x0002
  #define PA_HYP_WTIMES     0x0004
  #define PA_REF_WTIMES     0x0008
  #define PA_HYP_TIMES      0x0010
  #define PA_REF_TIMES      0x0020
  #define PA_HYP_CONF       0x0040
  #define PA_REF_CONF       0x0080
  #define PA_HYP_WEIGHT     0x0100
  #define PA_REF_WEIGHT     0x0200
  #define PA_HYP_SPKR       0x0400
  #define PA_HYP_ISSPKRSUB  0x0800
  
  typedef struct PATH_struct {
      int max;             /* maximum number of PATH_set structures in pset*/
      int num;             /* the current number of used structures in pset*/
  
      PATH_SET *pset;      /* the array of structures */
      
      char *id;            /* utterance id */
      char *labels;        /* any labels attached to the id's */
    
      char *file;          /* audio from whence the data came, only in place 
  			    for data aligned by ctm or stm */
      char *channel;       /* channel . . . ditto */
  
      double ref_t1;        /* beginning time for the reference */
      double ref_t2;        /* ending time for the reference */
  
      double hyp_t1;        /* beginning time for the hypothesis */
      double hyp_t2;        /* ending time for the hypothesis */
  
      int attrib;          /* an attributes of the path */
  
      int sequence;         /* Sequence number: during alignment */
  } PATH;
  
  PATH *PATH_alloc(int size);
  void PATH_print(PATH *path, FILE *fp, int max);
  void PATH_n_print(PATH *, FILE *, int from, int to, int max);
  void PATH_print_html(PATH *path, FILE *fp, int max, int header);
  void PATH_n_print_html(PATH *path, FILE *fp, int from, int to, int max, int header);
  void PATH_print_wt(PATH *path, FILE *fp);
  void PATH_increment_WORD_use(PATH *path);
  void PATH_free(PATH *path);
  void PATH_add_utt_id(PATH *path, char *utt_id);
  void PATH_add_label(PATH *path, char *label);
  void PATH_add_file(PATH *path, char *file);
  void PATH_add_channel(PATH *path, char *channel);
  void PATH_set_sequence(PATH *path);
  void check_space_in_PATH(PATH *path);
  void PATH_append(PATH *path, void *ap, void *bp, int eval);
  void PATH_remove(PATH *path);
  void sort_PATH_time_marks(PATH *path);