as there are partitions. And Shmuel said: One may move an object in it only within four cubits, as the partitions of the ship are not considered full-fledged partitions; they are erected only to keep water out, not to render it a residence.

Rav Ḥiyya bar Yosef said to Shmuel: Is the halakha in accordance with your opinion or is the halakha in accordance with the opinion of Rav? Shmuel said to him: The halakha is in accordance with the opinion of Rav, as his rationale is more convincing.

Rav Giddel said that Rav Ḥiyya bar Yosef said: And Rav concedes that if one overturned the ship onto its mouth, and it is more than ten handbreadths high, that one may move an object on it only within four cubits. The Gemara asks: For what purpose was the ship overturned? If you say it was overturned so that one may reside beneath it, what is the difference between it and an isolated roof? The legal status of the overturned ship should in every sense be that of a house, and therefore it should be permitted to carry throughout the entire ship.

Rather, it must be that he overturned it to tar it, i.e., to add a fresh coat to its underside. In that case, the boat certainly does not serve as a residence, and its sides are not considered full-fledged partitions.

Rav Ashi teaches Shmuel’s acceptance of Rav’s opposing view (Ritva) with regard to a ship, as stated above; and Rav Aḥa, son of Rava, teaches it with regard to a portico, as it was stated that amora’im disagreed with regard to a portico located in a field. A portico has a roof and either incomplete walls or no walls. Consequently, in the case of a portico located in a valley, which is a karmelit, it remains to be determined whether or not it is permitted to carry in it. Rav said: It is permitted to move an object throughout the entire portico, as it is a private domain. And Shmuel said: One may move an object in it only within four cubits.

The Gemara elaborates. Rav said: It is permitted to move an object throughout the entire portico, as we say: The edge of the roof descends to the ground and seals the portico on all sides, rendering it a private domain. And Shmuel said: One may move an object in it only within four cubits, as we do not say: The edge of the roof descends to the ground and seals the portico.

The Gemara asks: But according to Rav’s statement in accordance with the opinion of Rabbi Meir that one is permitted to carry from one roof to another if they are level, it should also be permitted to carry from a roof to a courtyard. Why then does Rabbi Meir rule that roofs and courtyards are separate domains and that carrying between them is prohibited? The Gemara answers: It is prohibited because Rabbi Meir issued a decree, due to the opinion of Rav Yitzḥak bar Avdimi. As stated previously, Rav Yitzḥak bar Avdimi rules that one may not transfer objects between two halakhically equivalent but physically distinct domains ten or more handbreadths high. This is a decree lest one standing in a public domain adjust a burden on a mound ten handbreadths high and four handbreadths wide, which is a private domain, an act prohibited by Torah law.

The Gemara continues: And according to Shmuel’s statement in accordance with the opinion of the Rabbis that the legal status of an isolated roof greater than two beit se’a is that of a karmelit, it should be permitted to move an object from an isolated roof to an enclosure within four cubits of the roof, as the legal status of the enclosure is also that of a karmelit. Why then do the Rabbis rule that roofs and enclosures are separate domains and carrying from one to the other is prohibited? Rava bar Ulla said: It is prohibited because the Rabbis issued a decree lest the area of the roof diminish to less than two beit se’a, in which case it would assume the status of a private domain, as it is prohibited to carry between a private domain and an enclosure.

The Gemara asks: If so, one should also not be permitted to move an object from one enclosure to another enclosure, due to the concern that perhaps the area of one of the enclosures will diminish and become a private domain, and he will come to move an object from one to the other as before. The Gemara answers: There, if the enclosure is diminished, the matter is conspicuous, as its walls are clearly visible. Here, however, if the roof is diminished, the matter is not conspicuous, as the roof does not have walls.

Rav Yehuda said: After careful analysis, you will find that you can say that according to the statement of Rabbi Meir, roofs are a domain in and of themselves, and one may carry from one roof to another; and likewise courtyards are considered a domain in and of themselves, and one may likewise carry from one courtyard to another.