MB4 240b: Partitions Between Two Chatzeros - part one (372:6-8)

If the wall between two chatzerot was 10 tefachim high on both sides (the chatzerot are at the same elevation) one can bring items resting on the wall into the adjacent chatzer but not into a house. This only applies if the wall is at least 4x4 tefachim. If the wall is within 10 tefachim of the ground of one of the yards, the residents of the other yard can't use the wall. What if there are ladders against the wall on each side?