def ordered_binary_search(ordered_list, item):
    """Binary search in an ordered list
    Complexity: O(log n)
    
    Args:
        ordered_list (list): An ordered list.
        item (int): The item to search.
    
    Returns:
        bool: Boolean with the answer of the search.
    
    Examples:
        >>> alist = [0, 1, 2, 8, 13, 17, 19, 32, 42]
        >>> sequential_search(alist, 3)
        False
        >>> sequential_search(alist, 13)
        True
    """
    first = 0
    last = len(ordered_list) - 1
    found = False

    while first <= last and not found:
        midpoint = (first + last) // 2
        if ordered_list[midpoint] == item:
            found = True
        else:
            if item < ordered_list[midpoint]:
                last = midpoint - 1
            else:
                first = midpoint + 1

        return found