∀ {R : Type u_3} {A : Type u_1} {B : Type u_2} [inst : CommSemiring R] [inst_1 : NonUnitalNonAssocSemiring A]
  [inst_2 : NonUnitalNonAssocSemiring B] [inst_3 : Module R A] [inst_4 : Module R B] [inst_5 : SMulCommClass R A A]
  [inst_6 : SMulCommClass R B B] [inst_7 : IsScalarTower R A A] [inst_8 : IsScalarTower R B B] [inst_9 : StarRing R]
  [inst_10 : StarRing A] [inst_11 : StarRing B] [inst_12 : StarModule R A] [inst_13 : StarModule R B] (x : A) (x_1 : B)
  (x_2 : A) (x_3 : B), star (x ⊗ₜ[R] x_1 * x_2 ⊗ₜ[R] x_3) = star (x_2 ⊗ₜ[R] x_3) * star (x ⊗ₜ[R] x_1)