Terminology: Parutz, breach. The case of "Parutz ke-omed," when the breached part and the wall part are equal - as disputed by R. Papa and R. Huna. Where the sources and the bottom line don't quite line up. Also, the new mishnah, that follows the previous mishnah. Setting up an eruv out of ropes, when you're on the go, and you need to make camp for Shabbat. Note the debate of horizontal vs. vertical elements of the enclosure. Is the caravan case (on the go) an example because it happened often or because it's the parameter? Plus trying to suss out how large an enclosure an individual could make in a personal camp.