def calculate_change(a, b):
    """ Calculate the difference between the x and y coordinates of two points.
  
    Arguments:
        a (tulpe): The x and y coordinates of the first point.
        b (tuple): The x and y coordinates of the second point.
    
    Returns:
        tuple: A new point containing the difference between the x and y
            coordinates of the points a and b.
            
    Examples:
        >>> calculate_change((1, 1), (1, 1))
        (0, 0)
        >>> calculate_change((1, 1), (3, 3))
        (2, 2)
        >>> calculate_change((5, 2), (-3, 4))
        (-8, 2)
    """
    return b[0] - a[0], b[1] - a[1]
