PK_range_result_t    


typedef int PK_range_result_t;


PK_range_result_t has three values:
    PK_range_result_found_c          separation successfully found
    PK_range_result_lower_c          minimum separation less than provided
                                     lower bound
    PK_range_result_upper_c          no separation discovered less than
                                     provided upper bound

In cases where a range function's option structure allows bounds to be set on
the separation distance, this data type is used to indicate whether an
allowed solution has been found.