והא אפשר לצמצם אמר רבי אמי במעדיף
The Gemara asks: But isn’t it possible to be precise? The mishna need not be understood in that manner, since it is possible to calibrate the width of the spaces to equal the width of the unfit roofing, as the mishna required no more than that. Rabbi Ami said: The mishna is referring to a case where one extends the width of the spaces beyond the width of the unfit roofing. The mishna deems the sukka fit only if the width of the spaces is greater than the width of the unfit roofing.
רבא אמר אפילו תימא בשאין מעדיף אם היו נתונים שתי נותנן ערב ערב נותנן שתי
Rava said: Even if you say that the mishna is referring to a case where one does not extend the width of the spaces, and nevertheless, the fit roofing is greater than the unfit roofing, if the skewers were placed lengthwise across the sukka, one places the fit roofing widthwise, and if the skewers were placed widthwise, one places the fit roofing lengthwise. By doing so, the fit roofing overlaps the skewers at least somewhat; otherwise it would fall between the unfit roofing. Consequently, even if the space equals the unfit roofing, the fit roofing is greater than the unfit roofing.
§ The mishna continues: Or with the long boards of the bed, which compose its frame, the sukka is unfit. The Gemara suggests: Let us say that the mishna supports the opinion of Rabbi Ami bar Tavyomei, as Rabbi Ami bar Tavyomei said: If one roofed the sukka with worn, incomplete, vessels, the sukka is unfit. Although these incomplete vessels are no longer susceptible to ritual impurity, they remain unfit because they were initially unfit for roofing. Proof can be adduced from the mishna: The long boards of the bed are no longer vessels but rather pieces from broken vessels; still, they may not be used for roofing the sukka.
The Gemara rejects this: The mishna is referring to a case similar to that which Rabbi Ḥanan said that Rabbi Yehuda HaNasi said in another context: It is not referring to the long boards alone. Rather, it is referring to a case with the long board of the bed and two of the legs attached to it or to a case with the short board of the bed with two legs attached to it. In this case, the structure could be propped up against a wall and used as a bed. Here too, the mishna is referring to roofing with the long board and two legs or with the short board and two legs, which are still considered complete vessels.