Review the גמרא דף ג. “ורב נחמן בר יצחק (eighteen lines from top of the Amud) until מאי אמלתרא (last narrow line of the Amud)
Bring a proof from the question and answer of the Gemara that Rebbe Yehuda’s opinion of maximum height is also for the reason of היכר.
See “חידושי הר”ן דף ג “קורה
(attached in Thursday’s email)
And “ריטב”א “קורה
https://hebrewbooks.org/pdfpager.aspx?req=37287&st=&pgnum=4
Continue learning the Gemara from מאי אמלתרא (last narrow line of the Amud) until the two dots.
Question:
Would one be permitted to place schach above 20 amos by placing an אמלתרא on the schach?
Continue learning the Gemara from the two dots until the last line of the Amud