What happens if one courtyard resident doesn't join the eruv?
The eruv requires all residents. One holdout invalidates it for everyone — the courtyard remains divided into separate domains.
Question 2
What is "bitul reshut"?
Bitul reshut: a person declares they renounce their rights to the shared space, removing their status as an independent domain. This saves the eruv when someone forgot to join.
Question 3
Can bitul reshut be done on Shabbat itself?
Bitul reshut can be performed on Shabbat — but only if the person hasn't yet carried into the courtyard. Once they carry, they've asserted their domain and can't renounce it.
Question 4
How is a non-Jewish resident's domain handled for eruv purposes?
Since a non-Jew can't participate in the Jewish communal eruv, their domain rights must be rented. This is a separate legal mechanism from the shared meal.
Question 5
Once a person carries an item into the courtyard (asserting their domain), can they still do bitul reshut?
Carrying = asserting domain rights. Once asserted, you can't take it back. Bitul must precede any assertion.