code: def _Dij(A, i, j):
      """Sum of lower-left and upper-right blocks of contingency table."""
      # See `somersd` References [2] bottom of page 309
      return A[i + 1 :, :j].sum() + A[:i, j + 1 :].sum()
  
label_desc: Use image node_id 2 for calling a global function with example usage: _Dij(A, i, j) and returns: unknown