struct PK_range_end_s
    {
    PK_ENTITY_t   entity;         --- entity at end of separation
                                  --- (PK_ENTITY_null)
    PK_ENTITY_t   sub_entity;     --- sub entity at end of separation
                                  --- (PK_ENTITY_null)
    PK_VECTOR_t   vector;         --- end position              (0.0, 0.0, 0.0)
    double        parameters[2];  --- parameter(s) at end position   (0.0, 0.0)
    PK_LOGICAL_t  region;         --- whether solution is regional
                                  --- (PK_LOGICAL_false)
    PK_LOGICAL_t  negative;       --- whether other end is inside body
                                  --- (PK_LOGICAL_false)
    };
typedef struct PK_range_end_s PK_range_end_t;




This structure records one end of a line of separation.


If the line of separation terminates on a curve, then `parameters[0]' will
record the curve parameter. If the line of separation terminates on a surface
then `parameters[0]' and `parameters[1]' will record the surface parameters.

When no sub_entity is identified, this field will be set to PK_ENTITY_null.