Eruvin 49a and Eruvin 49b, the three courtyards and how they do or do not combine, including in terms of a mavoi on either side, whether an eiruv can be split, and then a person who tries to make an eruv under a tree.
Eruvin 49a and Eruvin 49b, the three courtyards and how they do or do not combine, including in terms of a mavoi on either side, whether an eiruv can be split, and then a person who tries to make an eruv under a tree.