What is the significance of Ulah's statement about the seifah of the mishnah? And waht does Mar Zutrah mean with his response?
Ula is answering the Gemara's question: Why does the Beraisa say that it is permissible to handle an oil lamp on Shabbos (such as when it has become extinguished and is no longer burning, according to Rebbi Shimon in the Beraisa), but that it is prohibited to handle a Kos, Ke'arah, and Ashashis?
Ula answers that the statement of the Beraisa which prohibits moving a Kos, Ke'arah, and Ashashis is expressing the opinion of Rebbi Yehudah, who maintains that no oil lamp may be handled on Shabbos, except one that was never used (because all other lamps are Muktzah Machmas Mi'us). Similarly, Rebbi Yehudah prohibits moving a Kos, Ke'arah, and Ashashis.
Mar Zutra challenges Ula's answer. If this statement of the Beraisa is expressing the view of Rebbi Yehudah, then why does it say "Aval," implying a contrast to the previous Halachah? According to Rebbi Yehudah, it is the same Halachah.