---

def test0():
    x0 = float(2 ** (PRECISION + 1))
    x1 = x0 - 2.0
    x2 = -x1 / 2.0
    test_numbers0 = [x0, x1, x2, x2, x2, x2, x2, x2]
    n = ceil_log2(len(test_numbers0))
    pairwise_sum_result = pairwise_summation(test_numbers0)
    pairwise_sum_result_with_abs = pairwise_summation([abs(x) for x in test_numbers0])
    apriori_abs_error = pairwise_sum_result_with_abs * (n * UNIT_ROUNDOFF) / (1.0 - 2 * n * UNIT_ROUNDOFF)
    
    print("Pairwise Summation Result:", pairwise_sum_result)
    print("Pairwise Summation Result with Absolute Values:", pairwise_sum_result_with_abs)
    # В редакторе эта строка обрезана, но судя по выводу в терминале, она выглядит примерно так:
    print("A Priori Absolute Error Estimate:", apriori_abs_error)