∀ {R : Type u_3} {A : Type u_4} [inst : CommRing R] [inst_1 : NonUnitalRing A] [inst_2 : Module R A]
  [IsScalarTower R A A] [SMulCommClass R A A] (a b : A), quasispectrum R (a * b) = quasispectrum R (b * a)