theorem
kronecker_comm_of_comm
{A B C D : Matrix (Fin 2) (Fin 2) ℂ}
(hAC : Commute A C)
(hBD : Commute B D)
:
Commute (Matrix.kroneckerMap (fun (x1 x2 : ℂ) => x1 * x2) A B) (Matrix.kroneckerMap (fun (x1 x2 : ℂ) => x1 * x2) C D)
theorem
kronecker_observable
{A B : Matrix (Fin 2) (Fin 2) ℂ}
(hA : IsObservable A)
(hB : IsObservable B)
:
IsObservable (Matrix.kroneckerMap (fun (x1 x2 : ℂ) => x1 * x2) A B)