∀ {R : Type u_1} {A : Type u_2} [inst : Monoid R] [inst_1 : Monoid A] [inst_2 : MulAction R A] [SMulCommClass R A A]
  [IsScalarTower R A A] [inst_5 : StarMul R] [inst_6 : StarMul A] [StarModule R A] {r : R} {a : A},
  r ∈ unitary R → a ∈ unitary A → r • a ∈ unitary A