The adjustment of an alley — Beis Shammai say: A pole and a crossbeam. But Beis Hillel say: A pole or a crossbeam. R’ Eliezer says: Two poles. A disciple — in the presence of R’ Akiva — stated in the name of R’ Yishmael: Beis Shammai and Beis Hillel did not differ concerning an alley which is narrower than four cubits that it may be [adjusted] with a pole or a crossbeam. Concerning which did they differ? Concerning one which is wider than four cubits and up to ten cubits. Beis Shammai say: A pole and a crossbeam. But Beis Hillel say: A pole or a crossbeam. Said R’ Akiva: They differed in both cases.