 append_pi_list - appends the contents of the second list of phrase
                  indices to the members of the first phrase index list.
 build_pi_lists - builds lists of phrase indices referencing segmented
                  characters sorted into reading order based on
                  segmentor statistics.
 find_bubble_max_y - computes the maximum height of the bubble
                     given the line parameters for b = L(a).
 nearest_nbor_in_right_bubble - incrementally grows a bubble to the
                                right, retuning the nearest blob once
                                blobs are detected within the bubble.
 get_points_within_right_box - initially constrains the search space
                               to the rectangular region bounding the
                               largest possible bubble.
 get_list_in_right_bubble - searches the area within the current bubble
                            for the presence of blobs.
 is_in_right_bubble - determines if the specified point is within the
                      current bubble.
 nearest_nbor_in_left_bubble - incrementally grows a bubble to the
                               left, retuning the nearest blob once
                               blobs are detected within the bubble.
 get_points_within_left_box - initially constrains the search space
                              to the rectangular region bounding the
                              largest possible bubble.
 get_list_in_left_bubble - searches the area within the current bubble
                           for the presence of blobs.
 is_in_left_bubble - determines if the specified point is within the
                     current bubble.
 get_closest_pi_list_to_right - determines which list of phrase indices
                        is closest to the right of another specified
                        list of phrase indices.
 get_closest_pi_list_to_left - determines which list of phrase indices
                        is closest to the left of another specified
                        list of phrase indices.
 current_pi_list - determines if the next blob should be added to the
                   current phrase index list or be added to a new
                   phrase index list.
 find_pi_lists - given a list of segmented character centers, sorts the
                 blob indices into phrases according to proper reading
                 order.
 look_left - initializes the position of a new phrase by using the
             bubbles to look left of the specified position, attempting
             to begin the new phrase at the beginning of a line.
 pi_list_to_right - merge heuristic which determines if one list of
                    phrase indices is to the right of another list.
 pi_list_along_line - merge heuristic which determines if a list of
                      phrase indices lies sufficiently close to a line
                      projection defined by the given parameters.
 merge_pi_lists - collapses lists of phrase indices into complete lines
                  of text by applying two merge heuristics controlled
                  by the provided parameters.
 merge_pi_pair - appends the contents of two lists of phrase indices,
                 removes the merged list from the input lists, and
                 sorts the appended list's members on blob center x's.
 new_pi_list - allocates and initializes a new list of phrase indices,
               storing the top-leftmost blob's index into it.
 phrases2hypstr2 - appends the classes referenced in lists of phrase
                   indices into one long character string.
 phrases2constr2 - appends the confidences referenced in lists of phrase
                   indices into one long character string.
 process_nearest_pi - adds the next blob to the current phrase index
                      list and adjusts the bubble location statistics.
 remove_from_pi_lists - removes the specified list of phrase indices
                        from the given lists of indices.
 sort_pi_lists_on_y - sorts lists of phrase indices based on the
                      y coordinate of their first blob's center in
                      ascending order.
 sort_pi_list_on_x - sorts the elements of a list of phrase indices
                     based on the x coordinate of each blob's center in
                     ascending order.
 sort_pi_lists_by_length - sorts lists of phrase indices based on the
                           number of elements (blobs) in each list in
                           decending order.
 spell_phrases2 - takes a lists of phrase indices whose elements are
                  sorted into reading order and corrects errors and
                  identifies word boundaries using the specified
                  dictionaries.
 find_top_left - determines the top-leftmost blob of all the blobs not
                 yet assigned any phrase structure.
