function benchmark_fateman()
  print("benchmark_fateman ... ")
  R, x = polynomial_ring(ZZ, "x")
  S, y = polynomial_ring(R, "y")
  T, z = polynomial_ring(S, "z")
  U, t = polynomial_ring(T, "t")

  p = (x + y + z + t + 1)^20

  tt = @elapsed p*(p + 1)
  println("$tt")
end

