Daf Yomi - Sukkah 7 - Fruit in a Sukkah

Maharatz Chayus in Yoma 79 explains a Tosfos Yeshanim who seems to be saying contradictory statements. Tosfos Yeshonim writes that one is not required to enter a sukkah for eating fruit and he is discussing the Gemora which states that when eating fruit, a sukkah is needed. Maharatz Chayus explains based on a ruling of Rabbeinu Avigdor who states that even though one is obligated to eat in a sukkah when eating food only in the size of an egg, on Yom Tov, one is required to eat in the sukkah even for food which measures even an olive size. Tosfos Yeshonim maintains that this is true regarding fruits as well. During the week, one would not be obligated to eat fruit in a sukkah, however on Shabbos, where one can fulfill the mitzva of three seudos with fruit, he would be obligated to eat fruit in the sukkah.

This would be similar to our Gemora which states that if we consider something to be a wall regarding Shabbos, it is deemed a wall in regards to sukkah as well.