1)

(a)'Yesh bi'Mechitzos ha'Kerem Lehakel' - means, that if there are vines growing right up to the wall in a field, it is permitted to sow seeds on the other side of the wall, even by the entrance, where they will be growing literally side by side (although if there was no wall there, it would be necessary to maintain a distance of four Amos between one and the other).

(b)'Yesh bi'Mechitzos ha'Kerem Lehachmir' - means that, if the vines were growing eleven Amos from the wall, it would be forbidden to sow in between them and the wall (even though, if there had been no wall there, it would only require a distance of four Amos).

(c)We see from here, Rava asked Abaye, that there is such a thing as a Mechitzah Lehachmir.

(d)'Why did you ask me from the Beraisa?', Abaye asked Rava. 'Why did you not ask the same Kashya from the Mishnah in Kil'ayim'?

2)

(a)'Machol ha'Kerem' is basically the same case as that of the Beraisa, from which Rava asked Abaye.

(b)The reason that we need twelve Amos here, Abaye answered, is not because the Mechitzah creates a Chumra, but because the four Amos next to the vineyard are needed for Avodas ha'Kerem (to allow the animals together with the plow to go around the vineyard whilst plowing); four Amos next to the wall, because, one anyway tends to declare them Hefker in order not to spoil the wall; and the remaining space is only Chashuv if it is at least four Amos, but if it is less than that, it is not, and is Batel to the vineyard.

3)

(a)Rav Yehudah says that if three travelers made a joint Eruv in three adjoining Karfifos (of which the outer two are wider than the middle one), with one of the travelers in each Karpaf - we consider them like a a group of travelers (because we consider the residents of the two larger enclosures as if they were in the small one - as we learnt above [on 92a]), and a group of at least three travelers are permitted to carry in as large an enclosure as they need - even more than a Beis Se'asayim per person.

(b)Should the middle Karpaf be wider than the two outer ones ...

1. ... if one of the outer ones is more than a Beis Se'asayim - then it is forbidden (to carry there), while the others are permitted.

2. ... if the middle Karpaf is more than a Beis Se'asayim - then one may not carry in any of them, since the other two both open completely into a Reshus which is forbidden.

4)

(a)If in the case when the middle Karpaf is wider than the outer two, there are two travelers in the middle Karpaf and one in each of the outer ones - the Gemara asks whether we will say that since if the two in the middle are considered as belonging to one of the outer ones, then it will have three, and if they are considered as belonging to the other Karpaf, then it will have three. In that case, why should we not consider them as belonging to both Karfifos, to give all three an unlimited area to carry; or will we only consider one of the two travelers as belonging to one of the outer Karfifos, and the other one, to the other Karpaf, to give each outer Karpaf four thousand Amos - two Beis Se'asayim (but not both to both)?

(b)We do not consider the two middle ones as belonging to either one of the outer ones - because we can assume that, in order to gain space, they would prefer to spread out, one to one side, and the other to the other.

(c)Assuming that we go Lechumra and say like the second side of the previous She'eilah, asks the Gemara, perhaps when there are two in each of the outer Karfifos, and one in the middle one, we will definitely consider the one to belong to each of the outer ones, and give it the Din of a small group, or maybe one person cannot belong to two different sides, and since we do not know which one, we do not allow either of them an unlimited area.

(d)The Gemara concludes that we go Lekula in both She'eilos, to give the two outer Karfifos an unlimited area to carry.

5)

(a)When Rav Chisda says 'Gidud Chamishah, u'Mechitzah Chamishah, Ein Mitztarfin', he means - that if a five-Tefachim wall separates between two courtyards, one of which is five Tefachim lower than the other, they do not combine to make a Reshus ha'Yachid.

(b)This only pertains to the residents of the upper courtyard, who do not see a wall of ten Tefachim - but not to the lower courtyard, who do.

(c)The Beraisa, which permits both courtyards to make separate Eruvin - speaks when the upper courtyard did have walls of ten Tefachim up to the middle ten Amos, whose walls reached only as high as five.

(d)They cannot however, make a combined Eruv - since the lower courtyard has full walls separating it from the upper one.

6)

(a)According to Rav Chisda, the Seifa, 'Pachos mi'Kan, Me'arvin Echad v'Ein Me'arvin Shenayim' - speaks when the width of the lower courtyard is equivalent to the ten Amah Pesach of the large one - with no five Tefach wall in between them. In that case, it is open completely to the large one, and is forbidden to make its own Eruv.

(b)The upper courtyard is indeed permitted to make its own Eruv - 've'Ein Me'arvin Shenayim' pertains only to the lower one.

7)

(a)Mereimar say 'Gidud Chamishah u'Mechitzah Chamishah Mitztarfin', and the Halachah is like him.

8)

(a)The Beraisa, which forbids the residents of the small courtyard to carry, if the wall that divided them from the large courtyard breaks - seems to hold that new residents, who were not included in the Eruv, forbid carrying in the courtyard.

(b)Rabah however, refutes this proof - by suggesting that perhaps the dividing wall broke before Shabbos.

(c)Abaye failed to understand why Rabah said perhaps, when Rabah himself has already ruled 'Shabbos, Ho'il v'Hutrah Hutrah' c, with regard to a Pesach between two courtyards that became blocked.

9)

(a)Rav does not hold 'Ho'il v'Hutrah Hutrah'!

(b)Rav rules like Rebbi Shimon, who considers all the courtyards as one - but that only applies when they did not make independent Eruvin; when they did, even Rebbi Shimon will agree that each courtyard forbids the other.

(c)We know how Rav holds in this regard - from an episode in which a wall between two courtyard fell, and Shmuel instructed them to replace the wall with a sheet. Rav, who happened to be there at the time, turned round, to show that, in his opinion, they should not have carried the sheet in the courtyard.

(d)Rav turned round only to demonstrate that, Halachically, he disagreed with Shmuel's ruling.

10)

(a)Shmuel holds that, if the dividing wall breaks, each set of residents is permitted to carry up to the wall, because of 'Ho'il v'Hutrah Hutrah'.

(b)'Ho'il v'Hutrah Hutrah' means that what was permitted before remains permitted. That does not mean that what was forbidden before becomes permitted. Consequently, the Isur of carrying from one courtyard to the other remains in full force.

(c)Shmuel will permit carrying vessels which were in either of the courtyards when Shabbos entered to the other. (His Machlokes with Rav is confined to vessels which were in the houses when Shabbos came in).

(d)In fact, Shmuel did not really require the sheet at all, he only told them to put it up for reasons of Tzeni'us.