Sukkah 22: On a Boat, in a Tree, on a Camel, Oh, What Can Be?

A new mishnah! A sukkah that is "meduvlelet" and with more shade than sun, is kosher. That is, a sukkah with sparse schach. Alternatively, a disordered sukkah. The dispute here is between Rav and Shmuel, and the question is how many factors are contributing to this sukkah. Also, when can layers of schach combine to be one roof, and when would they be considered one on top of another? Also, the Gemara picks up on the shade being greater... And addresses what happens if shade and sunlight are equal - an equation that already came up and the Gemara resolves the issue here by focusing on where the light is coming from. Plus, another mishnah - if you build a sukkah on a wagon, on a boat, on a treetop, on a camel.... all kosher.