I wonder if you could just explain the opinion of the Rabonon on the 4th line of Sanhedrin 4b.

My initial thought was that (in contrast to Rebbi), the Rabonon are saying that the 2 dayonim above are the same as the two below, and we need a total of 2. (However, your Point-by-point explanation says 1 above and 1 below making 2).

Thanks in advance and Kol Tuv

Meir Eliezer Bergman, England