unkx80: I never seen this before. But I think after , Black can get at least a ko. Can Black do better?
char: I can't find anything better than a ko.
unkx80: Actually, this is the main line. I think the whole main line solution is about 30 moves long; how many amateurs can read this long without using a go board as an aid?
char: Let's open the can of variations =)
Since the two ladders are parallel, theoretically any white stone between them breaks both ladder.
However, playing a white stone at d or further doesn't work (the diagram on the right).