def right_of():
    """Returns a function that takes two 2D bounding boxes and computes whether
    the first one is strictly to the right of the second one.

    The output function takes in two 2D bounding boxes (dicts with keys 'x1',
    'x2', 'y1', 'y2') and returns ``True`` if the first bounding box's 'x1' value
    is greater than the second bounding box's 'x2' value.

    Returns:
        A function that takes two 2D bounding boxes and returns ``True`` if the
        first bounding box is strictly to the right of the second one.
    """
    return lambda bbox1, bbox2: bbox1['x1'] > bbox2['x2']
