A person eating a seudah on Hoshanah Rabbah wanted to continue eating his seudah when Shmini Etzeres already started. He was "pores mappah", made kiddush and continued to eat. Now, after a meal eaten wholly on Hoshanah Rabbah, one says "Sukkos" in Yaleh V'Yavo in Bircas HaMazon; after a meal eaten wholly on Shmini Etzeres, one says "Shmini Etzeres". So what about this felow who started on Hoshanah Rabbah and ended on Shmini Etzeres: When he recites Bircas HaMazon what day should be mentioned in Yaleh V'Yavo, "Sukkos" or "Shmini Etzeres"? What's the reason why and please cite all sources.
