Pictures Study Guide Eruvin 89 Today's Daf is sponsored by Stacey Goodstein Ashtamker in loving Memory of her much-missed mother Arlene Goodstein, Enya Bat Chana v' Moshe's 5th yahrzeit. "My mother's presence is felt every day with all the wonderful things she taught us, her love of Judaism and Israel, and all the strength she gave us. She would be very proud of her daughter studying Talmud." Can one carry from roof to roof or enclosure to enclosure or courtyard to courtyard? There are three opinions. What is the background to these approaches? According to the rabbis, the roof follows the house and one cannot carry from one to the other. Rav and Shmuel debate whether according to the rabbis one could carry on the roof itself or only 4 cubits?  Their argument depends on using imaginary walls (gut asik mechitzta) - in what situations can we use that principle?