test_clock = ->
  run_test [

    "clock(exp(i pi/3))",
    "(-1)^(1/3)",

    "clock(exp(-i pi/3))",
    #"-(-1)^(2/3)",
    "1/(-1)^(1/3)",

    "rect(clock(3+4*i))",  # needs sin(arctan(x)) and cos(arctan(x))
    "3+4*i",

    "clock((-108+108*(-1)^(1/2)*3^(1/2))^(1/3))",
    "6*(-1)^(2/9)",

    # TODO
    # the changes to abs/mag of Jan 2017
    # make it so a ends up as absolute value
    #     (-1)^(1/5)*abs(a)
    # Rather, clock should somehow recognize
    # that this is already very close to clock
    # form and just replace the exponential with
    # the power of -1
    # Note that this was working before the Jan 2017
    # changes because abs/mag were blissfully
    # transforming abs(any_variable) -> any_variable
    #"clock(exp(1/5*i*pi)*a)",
    #"(-1)^(1/5)*a",

  ]