Sukkah 24: Complete Severance

Remember "bereira"? It's here again. This time, in the context of a sukkah that relies on an animal being part of the sukkah. And wine that is in its wineskins, where terumot and maaserot have not yet been taken. Also, a shift to a discussion about gittin - Jewish divorce, and specifically the writing of the bill of divorcement. And the parameters of the writing of that divorce, as per the interpretations of the biblical phrasing. The back and forth here specifically is about the opinions of Rabbanan and R. Yosi HaGalili. Including defining the degree of severance between the divorcing couple. Plus, another mishnah: if you set up your sukkah between trees, the question is about the walls of the sukkah (without addressing the cover of leaves). Are the trees walls? Can they sway? They need to be tired down so that they, in fact, do not sway. Is this retroactive qualification of the tannaitic statement?