Eruvin 20A

תרי גווני אילן? הכא נמי, תרי גווני גדר.

that the baraita teaches two types of tree; here too, then, you can say that it teaches two types of fence, and therefore no proof can be brought from this baraita.

בעא מיניה אביי מרבה: חצר שראשה נכנס לבין הפסין ⁠— מהו לטלטל מתוכה לבין הפסין, ומבין הפסין לתוכה? אמר ליה: מותר.

And Abaye further inquired of Rabba: With regard to a courtyard, the open end of which interposed between the boards surrounding a well, what is the law with regard to carrying from inside the courtyard to the area between the upright boards, and from the area between the boards into the courtyard? Rabba said to him: It is permitted.

שתים, מאי? אמר ליה: אסור.

Abaye then asked him: And if two adjacent courtyards interposed between the boards surrounding a well, what is the law? Is it permitted to carry from inside them to the area between the boards, and vice versa? Rabba said to him in response: It is prohibited.

אמר רב הונא: שתים אסורין, ואפילו עירבו. גזירה שמא יאמרו ״עירוב מועיל לבין הפסין״. רבא אמר: עירבו מותר.

Rav Huna said: In the case of two courtyards, it is prohibited to carry, even if the residents of the two courtyards made an eiruv together. This is because of a decree lest they come to say that an eiruv is effective for the area between the upright boards. Rava, however, disagreed and said: If they made an eiruv together, it is permitted to carry between the courtyards and the area between the boards, and vice versa; with the preparation of the eiruv, the two courtyards are regarded as one.

אמר ליה אביי לרבא: תניא דמסייע לך ⁠— חצר שראשה אחד נכנס לבין הפסין מותר לטלטל מתוכה לבין הפסין ומבין הפסין לתוכה, אבל שתים אסור. במה דברים אמורים שלא עירבו, אבל עירבו מותרין.

Abaye said to Rava: What was taught in a baraita supports your opinion, for the baraita states: In the case of a courtyard, one end of which interposes between the upright boards surrounding a well, it is permitted to carry from inside the courtyard to the area between the upright boards, and from the area between the upright boards into the courtyard, but if there were two adjacent courtyards, this is prohibited. With regard to which case was this statement made? The statement applies where the residents of the two courtyards did not make an eiruv together; but if they made an eiruv together, it is permitted to carry between the courtyards and the area between the boards, and vice versa.