In this example det( O {\displaystyle {\mathcal {O}}} )=0, then Rank( O {\displaystyle {\mathcal {O}}} )<n and the systems is unobservable.
在此例中det( O {\displaystyle {\mathcal {O}}} )=0，因此Rank( O {\displaystyle {\mathcal {O}}} )<n，此系統不可觀測。