∀ {R : Type u_1} {S : Type u_2} [inst : NonUnitalNonAssocSemiring R] [inst_1 : NonUnitalNonAssocSemiring S]
  (e : R ≃+* S) (x y : ↥(Subsemigroup.center R)),
  (Subsemigroup.centerCongr ↑e).toFun (x * y) =
    (Subsemigroup.centerCongr ↑e).toFun x * (Subsemigroup.centerCongr ↑e).toFun y