Observation: Shmuel agrees about this, that the outer can be Mevatel to the inner, the Reshus that they have in it through putting their Eruv there, for [the inner] says [to the outer] "I joined with you to help myself, and not to harm myself!" It explains like this below (75b).

Explanation: Rava taught that Bitul is needed according to R. Akiva. According to Rabanan, also without Bitul, the inner says so [to the outer] and uproots their Eruv, for they say [that the outer] harm it;

However, R. Akiva says below (75b) that Bitul is needed, and when one of the inner people forgot, we cannot say so, that he be Mevatel to the inner people and close the door and it will use [its Chatzer by itself];

It cannot say "I joined with you to help myself, and not to harm myself!", for the beginning of the harm came through the person of the inner Chatzer [who forgot]. All this is from Rashi.

Question: What is Rava's source that Shmuel establishes it like R. Akiva, who requires Bitul? Perhaps it is Rabanan, who permit below without Bitul!

Answer: We heard that Shmuel said that [when] they forbid and [can be] Me'arev, they can be Mevatel, i.e. two Chatzeros, one inside the other. It is established only like R. Akiva.

Question: When one of the inner people forgot and was not Me'arev, and he is Mevatel to the people of the inner Chatzer, why does the outer forbid them, due to the Eruv that makes them frequent in [the inner Chatzer]? We said above (48b) that we do not say Diyurin (that an Eruv makes it as if they live together) to be stringent!

Answer: In the case above, there was no negligence. Here, the inner Chatzer was negligent and harmed itself.

Implied question: Above in our Sugya, when they put their Eruv in the outer, and one of the outer people forgot and was not Me'arev, he could ask so. Say that the outer person [who forgot] is Mevatel to the outer, and the inner comes and is permitted with them!

Answer: Here, the outer people are considered to dwell in the inner only through the Eruv, which makes them frequent. This is not considered Bitul from Chatzer to Chatzer;

This is because the outer people are automatically permitted, through that the inner person [who forgot] is Mevatel to the people of the inner, according to R. Eliezer, who says that he need not be Mevatel Reshus to every one;

However, above, the inner forbids the outer through its Drisas ha'Regel (rights to walk through it). Even though [the one who forgot] need not be Mevatel to every one, it is considered Bitul Reshus from Chatzer to Chatzer.

Explanation #1 (Rashi): This is unlike the case above, where the Nochri came on Shabbos, for here, if they wanted to rent and be Me'arev yesterday, they could have;

Rav Hamnuna says that they cannot be Mevatel. Since if they wanted to be Me'arev yesterday, they could not without renting, Bitul helps only in a place of Eruv (when they could have been Me'arev). Until here is from Rashi.

Question: Above (66a), it is obvious to us that when a Nochri came yesterday, they can be Mevatel. This is called "they forbid and they can be Me'arev";

It said above "if the Nochri came yesterday, they should have rented from him yesterday!"

Answer: We can say that the Sugya above is like Rav Sheshes, who says here that they can be Mevatel.

Question: However, it is difficult, for here it connotes that it is obvious to us that even Rav Sheshes holds that we do not do two matters (rental and Bitul), and only when [the Nochri] died [so they need not rent], they can be Mevatel, but if he did not die, and two matters are needed, i.e. rental and Bitul, we do not do [them];

Above, it is obvious to us that if the Nochri came yesterday, on Shabbos they may rent and be Mevatel. Only when he came on Shabbos, Shmuel said that they cannot be Mevatel!

Explanation #2: Here we discuss when he came on Shabbos and died on Shabbos.

Support: The words connote like this. It says "the question is according to the opinion that says that we do not rent. We do not do two matters";

[Rav Sheshes and Rav Hamnuna] argue when the Nochri came on Shabbos. Regarding this, [Rav Chisda] asked about when he died, whether or not we do one matter.

Question: Also when he did not die, one [matter] should suffice, i.e. Bitul alone, for [they are like] an individual in place of a Nochri!

Answer #1: I explained above (66a DH d'Asa) that they are not permitted through Bitul alone when the Nochri consents to rent, since if he would not consent, it would not be permitted, for if so, you are Mevatel the law of Eruv.

Answer #2: Rav Chisda holds like R. Meir, who forbids an individual in place of a Nochri!

Consequence: According to Answer #2, we cannot say "the question is according to the opinion that we may not rent" refers to Shmuel, for in any case Shmuel holds that Bitul suffices, for he said (62b) that the Halachah follows R. Eliezer ben Yakov (who says that a Nochri forbids only when two Yisraelim forbid each other. Through Bitul, they do not forbid each other), and above (66a) Shmuel said that they cannot be Mevatel;

Inference: Shmuel holds that we do not do even one! Rather, [the opinion that we may not rent] is R. Asi, who said above (65b) that we may not rent.

Implied question: Regarding two houses [on opposite sides of Reshus ha'Rabim, and on Shabbos Nochrim made walls, Rav Sheshes holds that] we are not Mevatel!

Answer #1: There, they do not forbid [each other], and they could not be Me'arev, for it was Reshus ha'Rabim before Shabbos. (Shmuel requires both for Bitul to help.) Here they forbid, and also they could be Me'arev until the Nochri came.

Answer #2: Regarding two houses, he did not have power before Shabbos to do the same Bitul he does now. Here, before Shabbos he had power to be Mevatel.

Explanation #1 (Ri): If it was Hukaf l'Dirah, he forbids even Beis Sa'atayim. Since it was Hukaf l'Dirah, it is like his house, and it is not considered for the interior of the Mavuy, and the opening to the Mavuy still forbids.

Explanation #2 (Rashi): If it was more than Beis Sa'atayim, it forbids only if it was not Hukaf l'Dirah. If it was Hukaf l'Dirah, it does not forbid.

Inference: Based on this, R. Tam permitted a garden more than Beis Sa'atayim that was not Hukaf l'Dirah, to carry from it to outside, since there did not pass in front of it a full Reshus ha'Rabim, like an intercity road or the city square;

He permitted to hide the key in the garden, even though he stands outside and puts in the garden, or to take from it to outside.

Suggestion: Perhaps we distinguish between [a garden and] a rock, for there (a rock, we are lenient) because it is not common.

Rejection: The reason for this decree (one may transfer between a Karfef more than Beis Sa'atayim and the sea) is lest people [think that it is a Reshus ha'Yachid in every respect, and] carry in all of it. This reason applies also here.

Support: We cannot infer [like R. Tam] from a Beraisa in Shabbos (6a), which says that there are four Reshuyos of Shabbos;

If it were forbidden to transfer from a different Karmelis to a Karfef more than Beis Sa'atayim, we find five Reshuyos of Shabbos!

Explanation: This was before the Milah, like Rashi explained.

Support: We compare this Amirah (telling a Nochri) to Haza'ah (sprinkling Mei Chatas), which is for the Mitzvah to do [Korban] Pesach;

However, after the Milah, and due to danger, [Abaye] would not have said "we were not Me'arev!" For Piku'ach Nefesh (mortal danger), whoever is zealous is praiseworthy, like we say in Yoma (84b).

Explanation: [Rabah suggested to rely on Shituf] of the Mavuy. Rashi explained a Mishnah (73b) says that if they did Shituf in the Mavuy, they are permitted here and here (in the Mavuy and in the Chatzeros).

Criticism: He should not have brought from that Mishnah, for below in the Gemara we establish it totally like R. Meir, that we require Eruv and Shituf. The Mishnah means, if they also did Shituf [in addition to Eruv...]!

Rather, he should have brought a proof from the Beraisa below (71b) "and Chachamim say, they are Me'arev or do Shituf."

Implied question: Below (72b), Rav rules like R. Meir, who requires both [Eruv and Shituf]!

Answer #1: [Rabah] holds like R. Yochanan, who says that people conduct like R. Meir, but l'Chatchilah we do not do like him.

Answer #2: [Rabah] holds like the opinion that with bread, there is no argument that one suffices;

He said "let us rely on Shituf", i.e. if they did Shituf with bread.