Talmud sur Erouvin 1:9

And it was stated thus¹⁰Tosephta Sukkah1:13.: “Two regular and the third even one hand-breadth is qualified.” Rebbi Ḥiyya in the name of Rebbi Joḥanan: Two of four hand-breadths each and the third even one hand-breadth is qualified. Rav Hoshaia asked, what if the one hand-breadth one is put in the middle⁷⁴Normally one would expect that the two large walls form a right angle Γ with the third (rabbinic) rudimentary wall parallel to one of the larger ones. He asks whether the two large ones may be parallel and the third at right angles to them: ׀ _ ׀. Since up to three hand-breadths open space are disregarded, the distance between the two parallel walls can be up to 7 hand-breadths, qualified according to everybody. Therefore the answer has to be positive.? He came back and asked, if one of the four hand-breadths ones was put in the middle⁷⁵That the shape is ׀ _׀. In this case there are three walls of 4 cubits each but the missing part is larger than 3 hand-breadths., how is it? Rebbi Jacob bar Aḥa: Such a case came before Rebbi Yasa and he qualified it. And it was stated thus⁷⁶Tosephta 1:8. Since later the rule is compared to those for eruvin and kilaim, one has to assume that on each side the total length of the open space is less than the sum of the diameters of the columns (cf. Eruvin Chapter 1, Note 246.): “If a courtyard is enclosed by pillars, the pillars are like walls.” Does not a baraita disagree? If they are made according to the rules they are qualified, not according to the rules disqualified. They wanted to say, in the middle⁷⁷That “not according to the rules” means the small (rabbinic) wall in the middle.. Rebbi Samuel bar Rav Isaac said, if these are not opposite those⁷⁸A configuration like^׀ _ _׀ is disqualified.. Rav said, that one of one hand-breadth must be removed from the wall by one hand-breadth⁷⁹As explained in Note 74, with the permitted empty spaces the theoretical space covered by the one hand-breadth wall must be 7 hand-breadths.. Samuel said, even if it is arbitrarily close, one considers it as if distant⁸⁰It is enough if one has one hand-breadth and adjacent three empty ones.. Rebbi Abba, Ḥinena bar Shelemiah, Rav Jeremiah in the name of Rav: even if it is arbitrarily close, one considers it as if distant. Rebbi Jacob bar Aḥa said, Rebbi Joḥanan and Rebbi Simeon ben Laqish, one follows this one, the other one the other. Cahana and Assi came and asked before Rav following that of Samuel⁸¹Since the answer is not given, we do not know Rav’s real position.. Rebbi Jehudah bar Pazi in the name of Rebbi Joshua ben Levi: Only if it is within three hand-breadths like a lathe⁸²In order to be able to carry in a dead-end street (bordered by the walls of houses) with an eruv, the dead-end street must be separated from the public domain by a visible entrance. This can be effected either by making a symbolic door by putting a horizontal beam over the entrance (Note 6) or creating a symbolic entrance post by putting up a vertical lathe. As door-post it has to be on the wall bordering the street. According to our rules, “on” always means “within three hand-breadths.”.