(Rabah): R. Yehudah [who says that the Chatzer wall permits the pit] and R. Chananya ben Akiva agree with each other:

(Beraisa - R. Chananya ben Akavya): If a ledge [above water] is four Amos by four Amos, one may carve out a hole four by four Tefachim in the middle and draw water through it (10 Tefachim remain in every direction around it. We consider it as if what surrounds the hole was bent down, making a Mechitzah in every direction - see Perush Chai diagram, Perek 8 number 81, in the English Charts section. Rashba - we do not say Pi Tikra Yored v'Sosem because there is only one real wall, or because the ledge is sloped or does not have an even edge.)

Rejection #1 (Abaye): R. Yehudah permits due to Gud Achis Mechitzta (there is a wall, and we extend it downward). He did not say that we bend to make a Mechitzah!

Rejection #2 (Abaye): [On Amud b we will say that] R. Chananya permitted on top of Lake Teveryah, which is surrounded by steep banks, cities and Karfifos. (Mid'Oraisa it is Reshus ha'Yachid, and there is a Heker so people will not carry from Karmelis in other cases.) He did not permit elsewhere!

(Abaye): According to R. Chananya, if a board [above water] is just within three Tefachim of a solid wall, it must be four Amos long and more than 11 Tefachim wide [to permit drawing water through it - one carves out in the middle [of the side facing the wall] more than a Tefach [to complete four Tefachim from the wall] along the length of four Tefachim along the board. We consider the remainder of the board to be bent down - the other long side is 10 tall and four Tefachim wide, the short sides are 10 tall and over one wide and Lavud to the solid wall, so they are considered to be four wide].

If the board is vertical [and within three of a wall], it must be 10 Tefachim tall and over six Tefachim wide [we consider over a Tefach on each end to be bent towards the wall, so they are Lavud; four Tefachim remain in the middle].

(Rav Huna brei d'Rav Yehoshua): If a vertical board is near a corner, it must be 10 Tefachim tall and over two Tefachim wide. [We consider over a Tefach to be bent towards each wall. Through Lavud, each is four wide.]

Question (against Abaye (d)): In the Beraisa, R. Chananya requires the board to be four Amos by four Amos!

Answer: This is when [there is no wall nearby. It is supported on pegs;] it is like a [hollow] mortar. (One pounds into it.)

(Mishnah): If a channel of water passes through a Chatzer, they may not draw water from it [on Shabbos] unless they made a Mechitzah 10 Tefachim tall where the channel enters and leaves [the Chatzer];

R. Yehudah says, the wall [of the Chatzer] over the water suffices.

R. Yehudah: A case occurred in which Chachamim sanctioned drawing water from a channel in Eivel! (They relied on the wall of the Chatzer.)

Chachamim: That was permitted because the channel was less than the Shi'ur [to be a Karmelis].

(Gemara - Beraisa #1): They may not draw from the channel unless they made a Mechitzah where the channel enters and leaves. (Then it looks like the channel begins and ends in the Chatzer.) A Mechitzah in one of these places is not enough.

R. Yehudah says, the wall over the water suffices.

R. Yehudah: A case occurred in which a channel went from Eivel to Tzipori, and Chachamim sanctioned drawing water from it.

Chachamim: That was permitted because it was not 10 deep and four wide.

(Beraisa #2): If a channel of water passes [through a Chatzer or Mavoy] under windows [of houses]:

If it is less than three [Tefachim - this will be explained], one may not lower a bucket and draw water from it. If it is [at least] three, this is forbidden;

R. Shimon ben Gamliel says, if it is less than four, it is permitted. If it is four, it is forbidden.

Question: What must be less than three or four?

Answer #1: The channel itself must be less than three or four.

Rejection: Rav Dimi said in the name of R. Yochanan that a place less than four [by four Tefachim] cannot be a Karmelis. If Tana'im argue about this, he would have said so!

Answer #2: (The channel itself is 10 deep and four wide. It is a Karmelis. It has banks below the Chatzer.) The Beraisa teaches that if the banks are narrow enough [they are Batel to the Reshuyos on each side, so] one may Machlif (transfer from the Chatzer to the banks, and then to the channel).

Question: Rav Dimi said in the name of R. Yochanan that if a place [at least three Tefachim tall] is less than four by four [Tefachim], people of Reshus ha'Rabim or Reshus ha'Yachid may unload on it, as long as they do not use it to transfer [from one Reshus to the other].

Answer: R. Yochanan forbids Chiluf between Reshuyos mid'Oraisa (for if one would directly transfer between them, he would be Chayav). The Beraisa permits between Reshuyos [for which the Isur to transfer between them is] mid'Rabanan. (E.g. one of them is a Karmelis, or. both are Reshus ha'Yachid.)

Question: R. Yochanan forbids even Reshuyos mid'Rabanan!

(Mishnah): If a wall between two Chatzeros is 10 Tefachim tall and four Tefachim thick, the Chatzeros can be Me'arev individually, but not together;

If there are Peros on top of the wall, people from either Chatzer may alight on the wall and eat them, but they may not take them down.

If the wall was breached up to 10 Amos, the Chatzeros can be Me'arev individually or together, for it is like an opening;

If it was breached more than 10 Amos, the Chatzeros can be Me'arev together, but not individually.

Question: If the wall is not four thick, what is the law [on top]?

Answer #1 (Rav): Since both have access to it [and it is too small to be a Reshus unto itself, it is Batel to both Chatzeros]. Neither may carry there at all;

Answer #2: (R. Yochanan): People from either Chatzer may bring food up and eat it [but they may not transfer].

This is like R. Yochanan taught elsewhere:

(Rav Dimi citing R. Yochanan): If a place is less than four by four, people of Reshus ha'Rabim or Reshus ha'Yachid may unload on it, as long as they do not use it to transfer.

Answer: Really, Ze'iri taught this last teaching [in the name of R. Yochanan].

Question: According to Ze'iri, the Beraisa refutes R. Yochanan!

Answer: Ze'iri holds that the Beraisa discusses the width of the channel. Tana'im argue about Rav Dimi's teaching (that less than four is not a Karmelis. If R. Yochanan indeed said it, he surely acknowledged that Tana'im argue about it.)

Question: [Even if the channel is less than the Shi'ur for Karmelis when it enters the Chatzer, surely it is a Karmelis before this. Within the Chatzer] the channel should be like Chorei (holes open to) Karmelis [which are like Karmelis]!

Answer #1 (Abaye bar Avin and R. Chanina bar Avin): (Chorei Reshus ha'Rabim are like Reshus ha'Rabim. Karmelis is a mere stringency mid'Rabanan.) We do not say that Chorei Karmelis are like Karmelis.

Answer #2 (Rav Ashi): Even if we say that Chorei Karmelis are like Karmelis, this is only if they are close to the Karmelis. Here, the channel is far (Ritva - four Tefachim) from [where the channel is wide enough to be] a Karmelis.

Answer #3 (to Question (j) - Ravina): The case is, there are walls on both banks where the channel enters and leaves [the Chatzer], and there is a gap between the walls;

Chachamim hold like they taught elsewhere [that if the gap is less than three Tefachim, it is considered a solid wall due to Lavud], and R. Shimon ben Gamliel holds like he taught elsewhere [that Lavud applies to a gap less than four Tefachim].

(Mishnah): If a balcony is above water, one may draw water on Shabbos only if he makes a hole in the balcony and a Mechitzah 10 Tefachim tall above or below [the balcony, and surrounding the balcony, or around the hole if it is at least four by four Tefachim - Rashi; Rashba - above means extending down from the balcony, and below means sticking up out of the water].

Similarly, if two balconies are one above the other, and a Mechitzah was made only for the top one, both are forbidden unless they Me'arev together.

(Gemara): Our Mishnah is unlike Chananya ben Akavya!

(Beraisa - Chananya ben Akavya): If a ledge [above water] is four Amos by four Amos, one may carve out a hole four by four Tefachim in the middle and draw water through it. (We consider it as if the sides were bent down. We need not make actual Mechitzos!)

(R. Yochanan): R. Chananya permitted on top of Lake Teveryah, which is surrounded by steep banks, cities and Karfifos. (Mid'Oraisa it is Reshus ha'Yachid, and there is a Heker so people will not carry from Karmelis in other cases.) He did not permit elsewhere. (Even so, our Mishnah is unlike R. Chananya, for it always requires Mechitzos.)

(Beraisa): R. Chananya permitted three things to people of Teveryah:

They may draw water through [holes in] ledges [above the lake, like we explained];

They may wrap food in pods [of legumes. This will be explained];

They may dry themselves with towels [after bathing. This will be explained.]

Question: What did he permit regarding wrapping food in pods?

Answer (Beraisa): If one rose early to bring pods:

If he rose early in order that there will still be dew on them, the dew is Machshir (enables food to become Tamei. The seven liquids are Machshir only if one desired them);

If he rose early to avoid losing time from his work, it is not Machshir.

Normally, people of Teveryah intend to avoid losing time from work. (They are workers. Therefore, the dew on the pods is not Machshir.)