ɐɡˈɛn, æz wˈɛl æz ɪnðə kəntˈɪnjuːəs tˈaɪm kˈeɪs ænd ɪnðə dɪskɹˈiːt tˈaɪm kˈeɪs, wˈʌn mˈeɪ biː ˈɪntɹɛstᵻd ɪn dɪskˈʌvɚɹɪŋ ɪf ðə sˈɪstəm ɡˈɪvən baɪ ðə pˈɛɹ ɪz əbzˈɜːvəbəl ɔːɹ nˈɑːt.
Again, as well as in the continuous time case and in the discrete time case, one may be interested in discovering if the system given by the pair  is observable or not.