Very quickly review the “גמרא דף ב. “אמר רב יהודה אמר רב until “והא כי כתיב” (thirteen lines from bottom of the amud)
Question:
What is the need for the rabanan to give a large explanation of why they take the dimensions from פתח היכל and not פתח אולם as there is no pasuk that says the words פתח אולם ?
Learn the “גמרא דף ב. “והא כי כתיב” (thirteen lines from bottom of the amud) until דף ב: “בין לרבנן (second line of the Amud)
Questions:
What’s the halachic implications that Mishkan and Beis Hamikdash are interchangeable?
Learn תוס’ “אשכחן
Continue learning the גמרא דף ב: “בין לרבנן until “ורבי יהודה
Questions:
Are we learning from the size of the opening of the Heichal/Ulam the maximum height and width of a מבוי or just one of them?
Learn תוס’ “בין
Conclusion for the position of the Rambam
See מגיד משנה הלכות שבת פרק יז הלכה א for an explanation of the Rambam
https://hebrewbooks.org/pdfpager.aspx?req=14278&st=&pgnum=72
See ח’ גרי”ז עירובין for the Brisker Rav’s explanation of the Rambam
According to the Rashba, why does the fact that the fourth side of a מבוי is open to Karmilis or to a Reshus harabim impact whether the three walls of the מבוי can make this a Reshus Hayachid?