A lengthy discussion on how to understand the mishnah: R. Huna, R. Yehudah, R. Yehudah Ben Beteira, R. Meir, and Rabban Gamliel. So first, a view of each of their opinions. Also, a new mishna, tracking yibum cases of two brothers, who are each married, one dies, one does yibum, and now has two co-wives, the widow and his original wife. What happens if he dies? And a third brother was only born after the marriages and yibum? What if there was only ma'amar, not yibum?