Clarification: That speaks with regard to above (by the S'chach) ...

Reason: Because as far as the walls are concerned, the Gemara declared Kasher above (on Daf 7a) 'canes that are less than three Tefachim apart ...

Refuted Question: And the Gemara's Kashya from Mavoy is (therefore) justified, since it too, is speaking about on top (the horizontal beam).

Clarification: And the Gemara is asking according to both the opinion in holds (in the first Perek of Eruvin, Daf 12b) 'Koreh Mishum Hekeira' (that the purpose of a Koreh is as a remninder) and that holds 'Mishum Mechitzah' (to serve as a wall).

Question: If 'L'vud' does not apply in the middle, then where the shade exceeds the sunshine (later, on Daf 22a) ought to be Pasul, unless it is completely covered, and thick like a house, so that there are no holes?

Answer: This is not a Kashya, since it speaks here specifically where the air runs across the entire Sukah, so that the S'chach is split into two parts.

Implied Question: And Pasul S'chach less than four Tefachim that does not disqualify the Sukah even though we do not say 'L'vud' in the middle ...

Answer: Is not comparable to air ...

Reason: Since 'Mah Nafshach' - if it is more than three Tefachim, it has left the realm of 'L'vud', yet it does not render the Sukah Pasul, since it is not Chashuv enough to make a Chatzitzah, and to divide between the two sections.

Implied Question: The Seifa has the same text as the Reisha ...

Answer: And there are differences between them in other areas, in the tenth Perek of Maseches Ohalos ...

Implied Question: And it does not cite the entire Mishnah here ...

Answer: Because it is the way of the Gemara to be brief w hen citing Mishnayos from Seider Taharos.

Definition: In our Mishnah (above on Daf 17a) Rashi explains 'A Chatzer that is surrounded by an Achsadra (a sun-porch)' - 'This Chatzer', he says, 'is surrounded by houses which open into it on three sides ...

Definition (cont.): And in front of the houses there are Achsadra'os - on all three sides; these Achsadra'os are open, with no wall facing the Chatzer ...

Definition (cont.): And it speaks where they placed S'chach over the air of the Chatzer; and this Sukah has no walls other than the walls of the houses that divide between the houses and the Achsadrah.

Definition (concl.): And it transpires that the roof of the Achsadrah divides between the S'chach and the walls all the way round.

Clarification: Now if the Achsadrah is four Amos wide, then the Sukah is Pasul; less than that, it is Kasher, because we apply 'Dofen Akumah' ...

Precedent: In fact, this is similar to the cloisters of the Nochrim, which have a space where grass grows and which is surrounded by an Achsadra.

Clarification (cont.): If the roof of the Achsadra exceeds four Amos in width, and on the side of the Sukah it has 'P'tzimin' - posts that resemble windows less than three Tefachim apart, it is Kasher, since we apply 'L'vud' ...

Clarification (cont.): And it is where there are no posts that they argue - Abaye declares it Kasher, since we say 'Pi Tikrah Yoreid ve'Soseim' (The edge of the beam descends and stops up the gap) - which refers to the thickness of the beams of the roof - the thickness of their tops which ends on the side of the Sukah descends and closes up the gap on all sides.

Clarification (concl.): Whereas according to Rava it is Pasul, since we do not apply 'Pi Tikrahh Yoreid ve'Soseim', as he will explain later'. This is how Rashi explains the issue.

Implied Question: The reason that Rashi needs to explain that the Achsadrah has posts and is therefore Kasher due to 'L'vud' ...

Answer: Is because according to the second Lashon, Rava declares it Pasul, since he holds that we cannot apply L'vud in this case ...

Reason: Due to the fact that the posts are put there to serve the Achsadra and not for the air outside (that has now become a Sukah).

Introduction to Question: According to Rashi's explanation - that we say 'Pi Tikrah Yoreid ve'Soseim' even on all four sides, there is a Kashya from the Gemara, which will shortly conclude that if the middle wall is broken and only the two parallel walls are standing - like an open Mavoy ...

Introduction to Question (cont.): Abaye concedes that we do not apply 'Pi Tikrah Yoreid ve'Soseim' ...

Question: How much more so here, where there are no walls at all?

Answer: Rashi however, draws a distinction - in that it speaks there about a Chatzer where there is no sun-porch ...

Answer (cont.): When he explains "According to you, who says 'Pi Tikras Achsadrah Yoreid ve'Soseim", why not also say that a Sukah in a Chatzer that is covered with thick planks that are less than four Tefachim wide, and where the middle wall is broken and the two opposite walls are still standing ...

Answer (cont.): Is Kasher due to its 'Pi Tikrah (i.e. the edge of the planks) Yoreid ve'Soseim' ?

Answer (concl.): To which (Abaye) replied 'In such a case I concede to your opinion, since the air on the far side is open - similar to an open alleyway, in which case it is made as a shortcut, as a sort of public valley'.

Inference: His (Rashi's) words imply that he invalidates the Sukah more where the air of the Chatzer surrounds the S'chach than where the roof of the Achsadrah does ...

Inference (cont.): Because it bears a closer resemblance to an open alleyway ...

Refutation: But this is a strange S'vara?

Explanation #2: It therefore seems that when they initially argue over where one places the S'chach on an Achsadrah which has no posts, it speaks where there are two Kasher walls like a Greek 'Gama' (adjacent to one another), either east and south or east and north ...

Explanation #2 (cont.): Which one normally does to provide a certain amount of Tzeni'us ...

Explanation #2 (cont. [Abaye]): And even though there is no third wall at all, Abaye permits it via 'Pi Tikrah ... '.

Explanation #2 (cont. [Rava]): And Rava now asks Abaye whether in a case where the Sukah has two parallel walls, but not a middle one, he will also permit it via 'Pi Tikrah ... '?

Implied Question: And he mentions that 'It broke' (Hifchis), either ...

Answer #1: It is La'av Davka ...

Answer #2: Or because if it is initially made like that, the Lashon 'P'chisah' is also applicable.

Explanation #2 (cont. [Abaye]): To which Abaye responded 'In this point I agree with you that we do not apply 'Pi Tikrah ... ', since it resembles an open alley, where the Rabanan do not hold of 'Pi Tikrah ... ' ...

Source: As the Mishnah states at the end of 'Kol Gagos' (Eruvin , Daf 95a) where the Tana'im argue over a case where 'Someone builds an attic on top of two houses', because even Rebbi Yehudah, who permits (carrying) there, that is only with regard to Shabbos, since he holds that two walls are (a R'shus ha'Yachid) 'd'Oraysa' ...

Source (cont.): But as far as Sukah is concerned, where min ha'Torah three walls are required, he concedes that we will not say 'Pi Tikrah Yoreid ve'Soseim'.

Explanation #2 (cont. [Rava]): And Rava who asked the question, thought that even according to the Rabanan, who do not hold 'Pi Tikrah there, Abaye here says 'Pi Tikrah ... '

Reason: Because since it applies to a blind alley, where we would say 'Pi Tikrah ... ' if necessary, we will also apply it to an open Sukah.

Introduction to Question: However, according to what Tosfos just explained, there is a Kashya - since it implies in Perek Kol Gagos (Ibid. Daf 93a) that Abaye too, permits an open alley ...

Sugya in Eruvin (Rava): Since Rava said to Abaye 'Don't we find a Mechitzah that creates an Isur? ...

Sugya in Eruvin (Rava [cont.]): Since if one places S'chach on top of an Achsadrah that has posts (one Tefach wide), it is Kasher; whereas if he levelled off the posts (as we shall see shortly), it is Pasul?

Sugya in Eruvin (Abaye): To which Abaye replied 'According to me, it is Kasher, whereas according to you it constitutes a removal of the Mechitzos'.

Inference: It transpires that the 'Yesh lah Petzimin' there is not equivalent to the 'Yesh lah Petzimin' here, seeing as there they clearly argue (See Maharam).

Sugya in Eruvin (cont. [Rashi]): This is the explanation of the Sugya there according to Rashi: 'Sikach al Gabei Achsadrah she'Yesh lah Petzimin' - It has two walls according to the Halachah that run along its length and are shaped like a Mavoy, and instead of the third wall there are planks measuring a Tefach fixed on the corners, it is Kasher, as we learned in the Beraisa (See Hagahos ve'Tziyunim) 'Two walls like the Halachah, and the third wall even a Tefach'.

Sugya in Eruvin (cont. [Rashi]): 'Whereas if one levelled off the planks' - 'by building two walls inside beside (i.e. parallel to) the original walls, so that the planks are now placed in between the two walls on one side and in between the two walls on the other side, an they are not visible inside the Achsadrah.

Sugya in Eruvin (cont. [Rashi]): 'It is Pasul' - 'Since it only has two walls' ...

Sugya in Eruvin (cont. [Rashi]): 'According to me (Abaye) it is Kasher' - 'I disagree with you on this point - because even if it has no walls, it is Kasher, since I hold "Pi Tikrah Tikra Yored ve'Soseim" ...

Sugya in Eruvin (cont. [Rashi]): Because a S'tam Achsadrah has beams affixed to the top from post to post, on which they place the ceiling; and those beams have an edge - which is the roof, which is not rounded but square.

Sugya in Eruvin (concl. [Rashi]): 'And even according to you, who holds that it is Pasul, there is no Mechitzah here that disqualifies it, and the reason here is because the planks and the original walls have been removed by the new walls, leaving the Sukah with them alone.

Question: Now according to the distinction that Rashi draws between an open Chatzer and and open Achsadrah, it goes nicely.

Question (cont.): But according to Tosfos explanation, there is a Kashya?

Sugya in Eruvin (Explanation #2): We must therefore say that the two walls there are not open (one opposite the other), but are shaped like a 'Gama', as Tosfos explained earlier and the plank is placed in the location of the third wall - measuring one Tefach; and there are four planks on the four corners of the Achsadrah - since it is the done thing to place beams from one column to the next, in order to build the roof of the Achsadrah on top of them ...

Sugya in Eruvin (Explanation #2 [cont.]): And those columns protrude one Tefach at the ends of the walls. And when 'He levelled off the planks' - by making other walls parallel with the original two in the shape of a 'Gama' on the inside of the planks, so that they are no longer visible inside the Sukah (Rava declares it Pasul).

Sugya in Eruvin (Explanation #2 [concl.]): Nevertheless it is Kasher according to Abaye, due to 'Pi Tikra ... ', even if there would be no walls at all.

Our Sugya: But the planks in our Sugya, over which they argue in the second Lashon in connection with 'L'vud', we need to establish where it is surrounded by many planks, where there are no walls at all, and where those planks serve as walls based on 'L'vud'.

Reconciling the Two Sugyos: If we now want to equate this Sugua with the Sugya in Eruvin, in which case it has two walls and the planks are used for the corners ...

Reconciling the Two Sugyos (cont.): We will have to explain that each corner has two planks next to each other within three Tefachim, each of which is not a Tefach thick - other than b y means of 'L'vud'.

Explanation #3 (conl.): And this certainly goes well with Rava, since we can now explain that he learns that it must be a Tefach without L'vud.

Reason: Since we only apply 'L'vud' to complete walls, but not to walls of aa Tefach.

Explanation #1: In Perek Kol Gagos (Eruvin, Daf 94b) Rashi explains that the Gemara mentions 'in a valley' because, an Achsadrah in a valley tends to be open on all four sides, and the walls stand on four 'pegs' ...

Explanation #1 (cont.): Whereas in the town, S'tam Achsadra'os are made close to a house or a Chatzer, and the wall of the house closes it up at the back 0 in which case Shmuel concedes that 'Pi Tikrah Yored ve'Soseim'.

Rashi's Opinion: This is in accordance with his text (at the beginning of 'Kol Gagos' - there, Daf 94:) 'Does Shmuel hold 'Pi Tikrah ... ?', and it answers 'When does he not hold 'Pi Tikrah Yored ve'Soseim', by four walls, but by three, he does

Rashi's Opinion (cont.): Which according to Rashi means 'When does he not hold 'Pi Tikra ... ? ', there where one needs to make four walls by closing the edge of the roof, such as by an Achsadrah, but three - where one complete wall is already standing, and 'Pi Tikrah' is required for only three, he considers Kasher'.

Question: The Gemara here, establishess Abaye like Rav, whereas Abaye just said 'In that case I agree with you since it is like an open alleyway'? ...

Question (cont.): So we see that even by two walls he does not hold 'Pi Tikrah ... ', how much more so where there are no walls at all?

Refuted Answer: And if we want to differentiate in that it is an Isur Karm'lis de'Rabanan ...

Refutation #1: Then we should say the same according to Rava?

Refutation #2: And besides, Rebbi Yehudah and the Rabanan, at the end of 'Kol Gagos' (Ibid. Daf 95a) argue in a case of two wals in the R'shus ha'Rabim, as to whether we say 'Pi Tikra ... ' or not?

Refutation #2 (cont.): And in the case of the valley, Rav would hold 'Pi Tikra ... ' even if there are no Mechitzos, if not for the fact that 'One is d'Oraysa and one is de'Rabanan'.

Explanation #2: Rabeinu Tam therefore has the opposite text, as does Rabeinu Chananel - 'When does he not hold 'Pi Tikrah ... ', when it has three', meaning when it has only three walls and thee fourth wall is completely open, which is the way an Achsadrah is generally made ...

Proof #1: As the Gemara says in Perek Lo Yachpor (Bava Basra, Daf 25b) - 'The world resembles an Achsadrah, as the north side is not surrounded (by the sun)'.

Proof #2: And the Gemara also says in 'ha'Kometz Rabah (Menachos, Daf 29b) 'Why was the world created with a 'Hey?' Because it resembles an Achsadrah ... whoever wants to take leave, can take leave'.

Explanation #2 (cont.): But with four' - when it has four walls, where it has four walls, only the fourth wall consists of two posts and a bit (on top), which has the status of a wall, even though more than ten Amos are open, he holds 'Pi Tikrah ...'.

Explanation #2 (concl.): Whereas Rav holds 'Pi Tikrah ... ' even if it is completely open, and even if it has only two walls - provided it is not open at both ends ...

Source: Since the Gemara asks in Perek Kol Gagos (Eruvin, Daf 94b) in connection with a house that is broken on two sides 'What is the difference between one side, where we say 'Pi Tikrah ... ', and two sides, where we don't?'

Source (cont.): And it answers that Rav is speaking on a corner, where the roof as placed at an angle'.

Question: And when the Beraisa says there in the same Perek (on Daf 93a) that in a case where one half of a house has a roof and the other half doesn't, and where there are vines on one side, one is permitted to sow seeds on the other side, because 'Pi Tikrah Yored ve'Soseim'.

Question (cont.): Even though it does not have the status of four walls ...

Answer: One cannot compare Kil'ayim to Shabbos, seeing as by Kil'ayim, even the corners are permitted ...

Source: As the Gemara states in the first Perek of Eruvin (Daf 11a).

Implied Question: And the reason that it mentions 'a Valley' here, according to Rabeinu Tam ...

Answer #1: One may attribute to the fact that 'a valley' is a location where carrying is prohibited, since a valley is a Karm'lis.

Answer #2: Or because it is also speaking about an Achsadrah that has two walls, because there too, Rav holds 'Pi Tikrah ... ', provided it is not open at both ends, as Tosfos explained earlier ...

Answer #2 (cont.): And if it had mentioned an Achsadrah in a Chatzer, it would have implied specifically one that has three walls ...

Source: Since a regular Achsadrah in a Chatzer stretches along the entire length or breadth of the Chatzer, but here it only goes up to the middle of the Chatzer, and it is completely open to the inside.