Answer #2 (Shmuel): It is where he sleeps.

Question (against Rav - Beraisa): Shepherds, people who guard figs or other produce, and people who dwell in huts:

If they normally sleep in the city, they are like city dwellers [regarding Shevisah];

If they normally sleep in the field, they have 2000 Amos in every direction [from there].

Answer: There, without any doubt if we would bring their food to the field, they would prefer to eat there.

Rav Yosef: I never heard this teaching [of Rav].

Abaye: You taught it to us regarding the following teaching!

(Mishnah): If brothers eat at their father's table and sleep in their own houses, each of them must be Me'arev.

Suggestion: This shows that the place of sleeping determines [residence]!

Rejection (Rav Yosef citing Rav Yehudah): The case is, they receive Pras (are fed) from their father [but eat in their own houses].

(Beraisa): If five co-wives or five slaves receive Pras from their husband or master [each has his or her own house in the Chatzer]:

R. Yehudah ben Beseira permits the women [without an Eruv. They are drawn after the residence of their husband] and forbids the slaves;

R. Yehudah ben Bava permits the slaves and forbids the women. (Tosfos R. Peretz - no one else resides in the Chatzer. Surely, wives and slaves are not drawn after their husband or master more than sons are drawn after their father.)

(Rav): R. Yehudah ben Bava learns from "v'Daniel bi'Sra Malka" - wherever a slave is, it is as if he is in the king's gate.

We already taught whether a son is drawn after his father. (If the son eats (Rav) or sleeps (Shmuel) in his own place, he does not follow his father);

R. Yehudah ben Beseira and R. Yehudah ben Bava argue about whether wives or slaves are drawn after their husband or master.

Question: Is a Talmid drawn after his Rebbi [if he receives Pras from him]?

Answer: When Rav learned by R. Chiya, he said 'we need not be Me'arev, for we rely on R. Chiya's table. R. Chiya said similarly when he learned by Rebbi.

Question (Abaye): If five were Me'arev together, can one take the Eruv elsewhere (to join with another Chatzer), or must each be Me'arev?

Answer (Rabah): One can be Me'arev for all of them.

Question (Abaye): Brothers are like people who were Me'arev, yet our Mishnah requires each to be Me'arev!

Answer (Rabah): The case is, there are others in the Chatzer with them. Since others forbid them [unless they are Me'arev], they force each to be Me'arev by himself.

Support (Seifa): This is when they put their Eruv in another house. If the rest of the Chatzer brought their Eruv to the father's house, or if no one else lives in the Chatzer, they need not be Me'arev. (This implies that in the Reisha, there are others in the Chatzer.)

Question (R. Chiya bar Avin): If Talmidim eat in an inn in the valley and sleep in the Beis Medrash, from where do we measure their Techum?

Answer (Rav Sheshes): We measure from the Beis Medrash.

Question: If one put Eruv Techumim within 2000, and came and lodged in his house, we measure from the Eruv (the food), even though he sleeps in his house!

Answer: (In both cases, he would prefer to eat and sleep in the same place, so we measure from there.) There, it is clear that he would prefer to sleep where his Eruv is [for he desires to go in that direction]. Here it is clear that Talmidim would prefer to eat in the Beis Medrash.

Question (Rami bar Chama): If a father and his children, or a Rebbi and his Talmidim live in an inner Chatzer (Rashi. Tosfos - they are the only residents in a Mavoy. Each has a house and Chatzer open to the Mavoy. Food is provided for the children or Talmidim, but they eat in their own houses,) are they considered like an individual or like a Rabim [for the following laws]?

If they are like an individual, they need not be Me'arev, hence they cannot forbid the outer Chatzer. A Rabim must be Me'arev. If they are not, they forbid the outer Chatzer (Rashi. Tosfos - if they are like a Rabim, they must be Me'arev, lest the law of Eruv be forgotten);

If you will say that they are like an individual, does a Lechi or Korah permit the Mavoy? (It permits a Mavoy only if houses and [at least two] Chatzeros are open to the Mavoy. If the Chatzeros belong to a father and son, are they like one Chatzer or two?)

Answer (Rav Chisda - Beraisa): If a father and his children, or a Rebbi and his Talmidim live in a Chatzer [without anyone else], they are considered like an individual. They need not be Me'arev. [Even so, since they are open to the Mavoy,] a Lechi or Korah permits their Mavoy.

(Mishnah): If five Chatzeros open to each other and to a Mavoy:

If the Chatzeros made Eruvim [with each other] but were not Mishtatef in the Mavoy, the Chatzeros are permitted, and the Mavoy is forbidden;

If they were Mishtatef in the Mavoy, everything is permitted. (The Gemara will explain the entire Mishnah.)

If they were Me'arev in the Chatzeros and Mishtatef in the Mavoy, but one person forgot to be Me'arev in the Chatzer, they are permitted everywhere;

If one person forgot to be Mishtatef in the Mavoy, the Chatzeros are permitted, and the Mavoy is forbidden;

This is because the relationship of the Mavoy to the Chatzeros is like Chatzeros to houses.

(Gemara) Observation: The Tana [of the Reisha] is R. Meir, who requires Eruvei Chatzeros in addition to Shitufei Mavo'os.

Question: The second clause says that if they were Mishtatef in the Mavoy, everything is permitted. This is like Chachamim, who say that it suffices to be Me'arev or Mishtatef!

Answer: (This is also like R. Meir.) It means that if they also were Mishtatef in the Mavoy [in addition to Eruvei Chatzeros], everything is permitted.

Question: The third clause says that if they were Me'arev and Mishtatef, but one forgot to be Me'arev, they are permitted everywhere;

Question: What is the case?

If the one who forgot was not Mevatel, why are they permitted?!

Answer #1: He was Mevatel.

Objection: The fourth clause says, if one forgot to be Mishtatef in the Mavoy, the Chatzeros are permitted, and the Mavoy is forbidden;

If he was Mevatel, why is the Mavoy forbidden?

Suggestion: R. Meir holds that Bitul does not work in a Mavoy.

Rejection (Beraisa - R. Meir): [...R. Gamliel said...] he (the Tzeduki) was Mevatel his Reshus [in the Mavoy] to you!'

Summation of objection: We must say that [in the fourth clause] he was not Mevatel. Surely, also in the third clause he was not Mevatel!

Answer #2 (to Question (1)): He was not Mevatel. (We must say that they are permitted because we rely on the Shituf, like Chachamim.)

Summation of question: (The Seifa says that Eruvei Chatzeros do not permit the Mavoy. It is like R. Meir.) Are the Reisha and Seifa R. Meir, and the middle (third) clause is Chachamim?!

Answer: The entire Mishnah is R. Meir. He requires Eruvin and Shituf lest children forget about Eruvin. Here we are not concerned, because most were Me'arev.

(Rav Yehudah citing Rav): The text of the Mishnah does not say that the Chatzeros open to each other.

Also Rav Kahana said so, either himself or in the name of Rav.

Question (Abaye): Why shouldn't it say that they open to each other?

Answer #1 (Rav Yosef): He holds that Shituf must be brought from each Chatzer to the Mavoy, and then to the Chatzer in which it will be placed. (If Chatzeros open to each other, we always forbid, lest the Shituf be brought from Chatzer to Chatzer, and not through the Mavoy.)

Question (Mishnah): If Reuven had two neighbors [in the Mavoy], and each owned wine in partnership with Reuven, they need not be Me'arev [even though the wine was not brought through the Mavoy]!

Answer: The case is, the wine was brought in [to the Mavoy] and out [to the Chatzer in which it was left - Tosfos].

Question (Mishnah): To Mishtatef in a Mavoy, [one is Mezakeh...]

The Mishnah does not require bringing it through the Mavoy!

Answer: There also, it was brought in and out.

Objection (Rabah bar Chanan): Will you say that if one is Mezakeh bread in his basket for Shituf, it does not help [because it was not brought through the Mavoy]?!

Suggestion: Indeed, it does not!

Rejection: Rav himself taught that if a group was eating together and Shabbos came, they can rely on the bread on the table for Eruv;

Some say, they rely on it for Shituf.

(Rabah): They do not argue. If they were eating in a house, they rely on it for Eruv. If they were eating in a Chatzer, they rely on it for Shituf [even though it was not brought through the Mavoy]!

Answer #2 (to Question (c)): Rav holds that a Lechi or Korah permits a Mavoy only if houses and Chatzeros are open to the Mavoy. (If the Chatzeros open to each other, they are considered like only one.)