1)

(a)The Stam Mishnah in Shabbos, which forbids carrying from a wall between two courtyards down into one of the courtyards (and which must be speaking at least in a case when they made an Eruv) - is a Kashya on Rebbi Yochanan (specifically, because he always rules like a Stam Mishnah) which rules like Rebbi Shimon even when the courtyards made their own Eruv.

(b)If not for Rebbi Yochanan's ruling, we would establish the Mishnah when they made an Eruv (like Rav).

(c)Rebbi Yochanan explains 'u'Vilevad she'Lo Yoridu Lematah' to mean - in the house (rather than in the courtyard, which is permitted).

(d)Rebbi Yochanan is not perturbed by Rebbi Chiya's Beraisa, because if Rebbi did not specifically forbid eating in the courtyard, where did Rebbi Chiya get it from (i.e. Rebbi overrides Rebbi Chiya)?

2)

(a)In the case of two courtyards flanking a ruin, only of which made an Eruv, Rav Huna maintains that we give the ruin to the courtyard which did not make an Eruv - because otherwise, we are afraid that they may carry the vessels which they carried from the house to the courtyard into the ruin (like Rav on 91a, whose disciple Rav Huna was).

(b)Chiya bar Rav quoting his father, says that we give the ruin to both courtyards, explaining this to mean that both are forbidden to carry.

(c)Rav forbids carrying the vessels from the courtyard which made an Eruv to the one which did not, but not vice-versa - because whereas in the former case, we suspect that they may carry vessels that were carried from their house, from their courtyard to the one which did not make an Eruv. This fear does not apply in the opposite case, since, having not made an Eruv, there are unlikely to be vessels from those houses in the courtyard. Nor are we afraid that they may carry vessels from the courtyard which made an Eruv back to their own, because people tend to use their own vessels, not somebody else's. In any event, if Rav would permit carrying from a courtyard which made an Eruv to a ruin, then why should he forbid carrying from a courtyard which made an Eruv to one which did not!?

(d)This is no proof, answers the Gemara. Because people tend to leave their things in a courtyard which is guarded, but not so much in a ruin, which is not (and on something which is not common, Chazal do not issue decrees).

3)

(a)If a large roof adjoins a small one, the Tana permits the owner of the large roof to carry vessels from his house to the roof - because the opening into the small roof, a gap in the wall, serves as a Pesach; but not the owner of the small one - which is completely open to its larger neighbor.

(b)For the above concession to apply (to the large roof), the gap would have to be no wider than ten Amos, otherwise, it is no longer a Pesach.

(c)The author of this Mishnah (who forbids the owner of the small roof to carry) could well be Rebbi Meir, who considers all roofs to be one Reshus - because that only pertains to vessels which were resting there when Shabbos entered, but not to those which came from the house, and which could well be the ones under discussion here.

(d)Assuming that we are dealing here with roofs which do have walls (but whose outer walls serve as the Mechitzos, on the basis of 'Gud Asik Mechitzasah', we would have to be speaking about flat roofs, because by sloping roofs, we do not say 'Gud Asik Mechitzasah'.

4)

(a)According to Shmuel, the Tana needs to mention this Din with regard to both two roofs and two courtyards, to teach us that the roofs, like the courtyards - are used by many people, otherwise, we would say 'Gud Asik Mechitzasah' (in spite of the fact that there is no gap between the roofs) and the small roof too, would be permitted).

5)

(a)Rabah, Rebbi Zeira and Rabah bar Rav Chana deduce from our Mishnah - that the residents of the large area prevail over those of the small area (to include them in their number), but not vice-versa.

(b)Consequently, if there are vines in ...

1. ... the large field, it is as if they were also in the small field, and it is forbidden to sow seeds there.

2. ... the small field, it is permitted to sow seeds in the large one.

(c)Seeing as the large field has a Mechitzah whose Pesach is considered as if it was completely closed - one may sow right up to the Pesach (even though there is nothing really dividing the seeds from the trees.

(d)Since he planted his trees with permission, the owner of the vines is not obligated to uproot them (a penalty which is confined to those who planted or sowed illegally).

6)

(a)If the woman is standing ...

1. ... in the large courtyard and her Get is in the small one - then we consider the Get as if it were in the large courtyard and she is divorced.

2. ... in the small courtyard while her Get is in the large one - then she is not divorced.

(b)We cannot consider her to be in the large field (together with her Get), to declare her divorced - since she has not yet acquired the Get, so what will be gained by placing her with the Get (it is she who needs to acquire the Get and not vice-versa).

7)

(a)If the community are ...

1. ... in the large room, and the Shatz in the small one - it is considered a Minyan and they are Yotzei Tefilah b'Tzibur.

2. ... in the small room, and the Shatz in the large one - there is no Minyan and they are not.

(b)In the latter case, we do not consider the community to be in the large room, to consider them a Tzibur - because a minority can be considered a part of a majority, but not vice-versa.

8)

(a)With regard to reciting the Shema ...

1. ... if the person who wants to recite the Shema is in the small room, and there is excrement in the large room - it is as if he were in the large room and is forbidden to recite the Shema.

2. ... if the person who wants to recite the Shema is in the large room, and there is excrement in the small room - he may recite the Shema, because as far the large room is concerned, there is a Mechitzah which divides between the person and the excrement.

9)

(a)Abaye asked the Amora'im why, in the first case, when the vines are in the large field, seeing as, if there was no Mechitzah, it would be permitted to sow seeds beyond four Amos. Why then is it forbidden to sow at all in the small one - even more than four Amos away from the vines!? Since when does a Mechitzah create Isurim!?

(b)Rebbi Zeira cited the case of a large Chatzer adjoining a small one, where carrying in the large Chatzer is permitted, whereas if they were to extend the walls of the small Chatzer to cut right through the large one, it would be forbidden to carry in the large Chatzer, too.

(c)Abaye however, rejects that proof - because there, the new Mechitzos of the large Chatzer completely negate the old ones, rendering them ineffective; whereas in our case, why should the walls of the large field forbid sowing completely in the small one!?

10)

(a)Rava (or Rabah - see Tosfos DH 'Amar Lei') asked Abaye from a case quoted later (on 95a), where Rava holds that if one placed Sechach on top of a porch (which has two full walls), the Sukah is Kasher, because of the vertical one-Tefach thick posts which are visible from the inside (as we have learnt in Sukah - a Sukah is Kasher if it has two full walls and a third wall of one Tefach). Now if one were to build walls on top of the two existing ones, flush against the posts, the Sukah would become Pasul. So here we have a case, Rabah asks Abaye, where Mechitzos create a Pesul!?

(b)This proof too, Abaye refutes (according to Rabah and Rava's opinion regarding Sukah) on the same grounds as he refuted the previous one - namely, that the second set of Mechitzos completely negate the first ones, which cease to be effective.

(c)Abaye himself however, disagrees with the very basis of the proof. According to him, the Sukah is Kasher, even if a wall is built which covers the original posts - because of 'Pi Tikrah Yored v'Sosem' (The basis of their Machlokes will be explained later).

11)

(a)Rabah bar Rav Chanan cites the case of a house that is half covered and half open; if the vines are planted underneath the section that is covered, then it is permitted to sow in the open section right up to the vines (because 'Pi Tikrah Yored v'Sosem'); whereas if the ceiling was extended to cover the entire house, it would be necessary to distance the seeds at least four Amos from the vines - a clear example, claims Rabah bar Rav Chanan, of a Mechitzah, i.e. the ceiling, creating an Isur!?

(b)Here too, answers Abaye, it is not the extended ceiling which creates the Isur, but the fact that the original wall (formed by 'Pi Tikrah Yored v'Sosem') has now been negated.