Implied question: Why didn't Rav Huna teach this regarding two protrusions?

Answer #1: A Stam protrusion is within 70 Amos and a remainder from the primary part of the city. Since it is within the Ibur, even if there are protrusions more than 4000, we view them as if a string was stretched on them.

Implied question: [He could have taught about] when there are many protrusions one after the other, each within 70 Amos and a remainder from the previous, at the two ends of the city! (They are not within the Ibur, so this is just like a city like a bow.)

Answer: Perhaps we can distinguish. Protrusions that are not from the primary part of the city, even if the Techumim do not overlap, we add them to the city, for they are Batel to the city;

However, two ends of the bow, which are from the primary part of the city, they are not Batel to the city. Therefore, he requires overlap of Techumim.

Rejection (Ri, R. Chananel): It is unreasonable to distinguish between two protrusions and a city like a bow.

Answer #2: Rav Huna did not teach about two protrusions because [he wanted to teach about the Beraisa, and] the Beraisa does not discuss two protrusions from one direction, only one protrusion in each direction (but it teaches about a city like a bow).

Explanation: Below (55b), Rabah bar Rav Huna requires that there are not 2000 Amos between the [middle of the] Yeser (the line between the two ends of the bow) and the [middle of the] bow, because he requires overlap of Techumim on every side;

However, Rava the son of Rabah bar Rav Huna, who says that we measure from the Yeser even if there are more than 2000 Amos between the Yeser and the bow, because if he wanted, he could come [from the bow to the Yeser] via the houses, he is concerned that there be overlap of Techumim only from one side.

Assertion: According to him, the same applies if there is only 2000 between the Yeser and the bow. We measure from the Yeser even if there are more than 4000 between the two ends of the bow, for he could come along the Yeser from one end to the other, since the Yeser is enveloped within (R. E. M. Horowitz - the Techum of) the bow.

Explanation #1: We do not truly measure from the bow, rather, from where it narrows inside and there are less than 4000 Amos [between the two sides]. It is no worse than if the upper part (where it is wider than 2000; Tosfos discusses when the middle of the bow is below) were removed.

Explanation #2 (R. Chananel): The city is like a bow that does not get narrower. (It is like three sides of a rectangle. The two opposite sides are always the same distance apart.)

Explanation: Regarding Nefesh it mentions four Amos, and not Dirah, for Stam it is made for residence, like Rashi explained. Regarding a bridge and grave, it mentioned Dirah;

It did not mention four Amos (regarding a bridge and grave). This is not because Stam, they are four Amos, for a Stam grave is not four Amos!

Rather, since it mentioned a Beis Dirah, it is as if it mentioned four Amos, for less than four Amos is not a residence.

Explanation #1 (Rashi): The building is not four by four Amos. The cave completes it to four Amos.

Assertion (Ri): The building must be the majority of four [by four] Amos.

Explanation #2: The building has four [by four] Amos. It completes the cave to join it to the building. We begin to measure (2000 Amos) only from the end of the cave.

Explanation: [A Chacham must live in city with vegetables,] because they are cheap and he can engage in Torah.

Implied question: It says in Shabbos (140b) that a Talmid should not eat vegetables, because it arouses [appetite]. This implies that it causes him to spend much [money] for bread!

Answer: There we discuss raw vegetables. Cooked vegetables are good, and a small amount satiates.