(Mishnah): A small gutter (meant to keep rain away from a house wall) cannot create a chazakah; but the gutter owner has the right to use the place, even without the courtyard owner's consent.

A large gutter (that takes rainwater down the roof and to the ground below) can create a chazakah. A small ladder cannot create a chazakah (for its position in a courtyard); but a large ladder can.

A small window (opening to a courtyard) cannot create a chazakah (in the courtyard) but a large window can.

What is a small window? Small enough that a person's head could not fit through it.

R. Yehuda: If it has a wooden frame, even if a person's head could not fit through it, it can create a chazakah.

(Gemara) - Reish Lakish: (When the Mishnah taught that a small gutter cannot create a chazakah, it means that the courtyard owner can protest and prevent the gutter owner if he wishes to) lengthen or widen it. (However, he cannot insist on having the gutter removed completely.)

R. Yochanan: (When the Mishnah taught that a small gutter cannot create a chazakah, although the courtyard owner cannot have the gutter removed,) he can prevent the gutter owner from moving it around within that side.

Support (Beraisa): "A large gutter was given four amos around it (to allow the owner space to put up a ladder there in order to repair and clean it, meaning that if a neighbor wishes to build a wall near it, he must distance it four amos)." This is also the explanation of our Mishnah's ruling, "A large gutter can create a chazakah" - for all of that side.

It also explains the meaning of the Mishnah's ruling, "A small gutter cannot create a chazakah" for all of that side. Rather, it only creates a chazakah for the location that it is actually in.

Another support for R. Yochanan (Beraisa): The (exact) space of a small gutter in a courtyard has a chazakah but not the space of its stream, meaning that it cannot be moved to another place within that side.

D'Bei R. Yanai: (In discussing the Mishnah's ruling that a small ladder cannot create a chazakah, the Gemara cites an ambiguous statement from Maseches Shabbos) "Until the height of three rungs is considered a chair; more than that is considered a ladder". (The Gemara now brings a difference of opinion as to the application of that statement.)...

R. Ila citing R. Yanai: It was taught concerning tumah. (Until three rungs, its main use is for sitting and it can receive the tumah of midras. But a ladder of more than three rungs is mainly used for climbing and is considered a ladder that cannot receive the tumah of midras.)

R. Chizkiyah citing R. Yanai: It was taught concerning creating a chazakah (as in our Mishnah. Until three rungs is considered a small ladder that cannot create a chazakah; more than three, it can create a chazakah.)

R. Yosi citing R. Yanai: It was taught concerning the laws of Shabbos. (In the Bavli in Eiruvin 77a, the Gemara brings a discussion that certain ladders can be considered to be reducing the size of a wall that separates two courtyards. A small ladder can reduce it since it is portable and can be moved and used to climb the wall. However, a large ladder, which has more than three rungs, cannot reduce the wall because it is not portable.)

R. Hoshiyah: A small window only creates a chazakah in a courtyard. (Since it is small, a person cannot put his head into it to look at the neighboring courtyard.) But if such a window is on a roof, even if it is above four amos, a neighbor can prevent him having it since there is hezek re'iyah (damage from being able to be seen by the neighbor on the roof).

R. Hoshiyah heard that they had taught this statement in the Beis Medrash and he became angry. He said, "I was the one who said it and they did not quote it in my name!"