let update_and_tell_if_changed current_table kinstr d =
    let record = find_current current_table kinstr in
    if Cvalue.Model.is_reachable record.widening_state
    then
      let j = State_set.join d in
      if Cvalue.Model.is_included j record.widening_state
      then State_set.empty
      else State_set.singleton j
    else
      State_imp.merge_set_return_new d record.superposition