1)

(a)The reason that Rabah and Abaye's Mavoy had neither a Shituf Mavo'os nor an Eruv Chatzeros was because the great Rabah could not be expected to run around the Mavoy collecting bread for an Eruv, Abaye was so involved in his learning that he simply had no time to do it, and other residents of the Mavoy did not care sufficiently to get involved.

(b)Abaye did not donate a loaf of his own on behalf of the other residents of the Mavoy - because he could not afford to give it to them should they ask for it, and we have already learnt above, that bread which the owner is not prepared to give to any of those participating in the Eruv does not qualify as an Eruv.

(c)Nor could he simply designate one Revi'is in a barrel of vinegar - because Abaye holds 'Ein Bereirah', and this constitutes Bereirah.

2)

(a)A corpse in the house render all the windows Tamei, too - provided they are at least one Tefach by one Tefach.

(b)The vessels are not necessarily Tamei anyway because of Ohel ha'Mes, since we are speaking even in a case when they are not under the same Ohel - nevertheless, it is a Halachah le'Moshe mi'Sinai that any doorways or windows through which the corpse may pass are Tamei (unless one of them is specifically designated).

(c)If all the doorways are closed, and one of them is opened, or if all the doorways are less than four by four Tefachim, and one of them is more, then it is Tamei, and all the other ones remain Tahor.

3)

(a)According to Beis Shamai, Machshavah will not help after the man has died - because once Tum'ah descends on the doorways, it will only leave through an act (e.g. opening one of the doorways and all the rest are closed), but not through Machshavah, because 'Ein Machshavah Motzi mi'Yedei Machshavah'.

(b)However, vessels that were placed under one of the other doorways after the Machshavah - remain Tahor.

(c)According to Beis Hillel - Machshavah helps retroactively even after the person dies - even with regard to vessels that were there before the Machshavah (because they hold 'Yesh Bereirah').

(d)Abaye in 1c who says 'Ein Bereirah' holds like Beis Shamai.

4)

(a)Rava told them to ask the mother whether she needed hot water for herself. If she did, then they would be able ask a gentile to heat some water for her, and at the same time, for her baby too.

(b)The mother is only considered in a state of danger during the first seven days. From seven until thirty days, we believe her only to the point of permitting a non-Jew to prepare her needs for her, but not a Jew, including herself.

(c)If the mother was eating dates, and not hot foods, Rav Mesharshaya pointed out, it was clear that she did need hot foods.

(d)Rava replied that she was in a hazy frame of mind, and did not quite know what she was doing.

5)

(a)Rava had his vessels moved from the men's chambers (which had entrances to the courtyard) to the women's (which did not). Then he was Mevatel his Reshus from the Chatzer, thereby permitting the hot water to be carried from there to the Chatzer where the baby was.

(b)Moving his vessels from the men's Chatzer to the women's - was to ensure that he would not (inadvertently) carry them out into the Chatzer, as that would negate the Bitul that he had just made.

(c)Rava follows the opinion of Rebbi Yochanan, who holds that Bitul Reshus helps from one courtyard to another.

6)

(a)Ravina asked Rava - that, since he held like Rebbi Yochanan (who holds that 'Yesh Bitul Reshus me'Chatzer le'Chatzer'), he could have dispensed with the need to move his vessels to the ladies' chambers, by being Mevatel his Reshus to the residents of the Chatzer where the baby was for the time that was needed to transport the hot water there. After that, they could have been Mevatel it, enabling him to re-acquire it, so to speak?

(b)If Rava held like Shmuel ('Ein Mevatlin ve'Chozrin u'Mevatlin'), Ravina maintained, then he would hold that he has removed himself from his Chatzer completely for that day (to become like a resident in another Chatzer). But surely the reason for that is because he holds 'Ein Bitul Reshus me'Chatzer le'Chatzer' (Shmuel's other Din). So how can Rava hold 'Yesh Bitul Reshus me'Chatzer le'Chatzer'?

(c)Shmuel's real reason for saying 'Ein Mevatlin ve'Chozrin u'Mevatlin' - answered Rava - is because to do so makes a mockery of the Takanah of Bitul (and not because of 'Ein Bitul Reshus me'Chatzer le'Chatzer').

7)

(a)The Gemara thinks that Rav says 'Mevatlin ve'Chozrin u'Mevatlin' - because, in his opinion, even after Bitul, the owner still retains some ownership over his original residence. This conforms with the opinion of the Rabbanan, who forbid the other residents to carry from the house of the one who was Mevatel Reshus for the very same reason (because he still retains ownership of his house); Consequently Shmuel, who holds 'Ein Mevatlin ve'Chozrin u'Mevatlin' - will follow the opinion of Rebbi Eliezer (because they both hold that the owner relinquishes his ownership completely, when he makes Bitul).

(b)In fact, Rebbi Eliezer could well agree with Rav (that even after Bitul in the Chatzer, the owner still retains, or at least, leaves himself the option of retaining, some ownership over his original residence) - he maintains however, that a person does not usually live in a house without a Chatzer (which is why Bitul Reshus of the Chatzer extends to the house).

(c)The Rabbanan, on the other hand, may well hold that Bitul on the Chatzer does not necessarily mean Bitul on the house. However, from whatever he is Mevatel his Reshus, that Bitul is total (like Shmuel).

8)

(a)

1. Rebbi Meir forbids the other residents to continue carrying if the Mevatel subsequently carries out from his house into the Chatzer, even be'Shogeg - because he holds that he still retains ownership of his portion in the Chatzer - like Rav, who holds 'Mevatlin ve'Chozrin u'Mevatlin'.

2. Rebbi Yehudah permits them to carry (if he took out the vessels be'Shogeg), because he maintains that the Mevatel does not retain ownership - like Shmuel who holds 'Ein Mevatlin ve'Chozrin u'Mevatlin'.

(b)If he carried out be'Meizid, then both Tana'im will agree that, since the Mevatel expressly intended to re-acquire ownership, he does indeed re-acquire it. Strictly speaking, when he carries his vessels into the Chatzer be'Shogeg, it ought to have no effect at all (since, initially, he completely relinquished his ownership); and that is the opinion of Rebbi Yehudah. Rebbi Meir however, holds, that they gave Shogeg the Din of Meizid in this case, and forbade the other residents to continue carrying there.

(c)The other residents could prevent the Mevatel from re-acquiring his rights in the Chatzer - by making a Chazakah i.e. using the Chatzer first.

9)

(a)The Gemara amends the Mishnah to read - 'Tzedoki, Harei Hu k'Nochri. v'Rabban Gamliel Omer, Tzedoki Eino k'Nochri'.