# Genearte the true derived position list {LB0,IB0}:
      LB0,IB0 = 
     
      # Now generate various candidates {LB,IB} and 
      
  
      C = 

    # Generate a list {LB1} with 
    
    # Now generate various lists {LB} with various numbers of
    # preserved positions:
    
      # Generate a list {LB0} of {nB} random positions, with min separation {min-sep}:
      LB0, IB0 = insert_random_valitions(nB, max_val, min_sep, [])
      assert len(IB0) == 0
      
       ???
       ???
      
        # Select the {nK} indices in {LA} to preserve, and their matches in {LB}: 
        IA = random_index_subset(nK, nA)
        IB = random_index_subset(nK, nB)
        # Generate a list {LB1} of {nB} positions from {LA} by the delete-shift-insert method:
        LB1 = simulate_del_shift_add(nB, IB, LA, IA, max_val, pert_dev)
        test_sub_sub_match_quality_given_IB_IA(LB, IB, LA, IA, max_val, pert_dev) 
  return
  # ----------------------------------------------------------------------