anchor.diff:      candidates(2, 1)%nodes(1, :) = [1.0_dp, 1.25_dp]
       candidates(2, 1)%nodes(2, :) = [0.0_dp, 2.0_dp]
   
  -    case_success = .NOT. allocated(intersections)
       call intersect_one_round( &
            num_candidates, candidates, num_intersections, intersections, &
            next_candidates, num_next_candidates, py_exc)
       case_success = ( &
  -         case_success .AND. &
  -         .NOT. allocated(intersections) .AND. &
            num_intersections == 0 .AND. &
            num_next_candidates == 0 .AND. &
            py_exc == FROM_LINEARIZED_SUCCESS)
  
positive.code:          associated(intersections(1)%first, first) .AND. &
           associated(intersections(1)%second, second))
      call print_status(name, case_id, case_success, success)
      deallocate(intersections)
      num_intersections = 0
  
      ! CASE 2: Lines that **do not** intersect.
  
negative.code:          status == ALL_INTERSECTIONS_TOO_MANY)
      call print_status(name, case_id, case_success, success)
      deallocate(candidates)
  
      ! CASE 5: Badly scaled curves, which cause the subdivision proceass to
      !         take too many iterations before being "almost linear".
  