958. Eiruvin Without a Shittuf; A Shittuf Without Eiruvin

Eiruvin 5:13

Let’s say that each courtyard in an alley made an eiruv for itself, after which they all joined together in a shittuf for the alley. If one of the alley residents forgot to join his courtyard’s eiruv, he suffers no consequences. Since they all joined together in a shittuf, they rely upon the shittuf. The only reason it is necessary for the courtyards to make an eiruv along with the shittuf is so that the children won’t forget that there’s such a thing as an eiruv. However, if one of the alley residents forgot to participate in the shittuf, carrying in the alley becomes prohibited but the residents may carry in their own courtyards. A courtyard is to its alley as a house is to its courtyard.

Eiruvin 5:14

Let’s say that all the residents of an alley participated in a shittuf but they forgot to make eiruvs for their courtyards. If they are forthcoming when it comes to sharing bread, then they may rely on the shittuf alone for just one Shabbos. This one-time leniency is extended because of the difficulty the situation presents.