def METHOD_NAME(par):
    """Solve inversion with a skinny regularization (rows are smaller than
    the number of elements in the model vector)
    """
    np.random.seed(10)
    d = np.arange(par["nx"] - 1).astype(par["dtype"]) + 1.0
    Dop = Diagonal(d, dtype=par["dtype"])
    Regop = HStack([Identity(par["nx"] // 2), Identity(par["nx"] // 2)])
    x = np.arange(par["nx"] - 1)
    y = Dop * x
    xinv = normal_equations_inversion(Dop, y, [Regop], epsRs=[1e-4])[0]
    assert_array_almost_equal(x, xinv, decimal=2)
    xinv = regularized_inversion(Dop, y, [Regop], epsRs=[1e-4])[0]
    assert_array_almost_equal(x, xinv, decimal=2)