Bava Mezia 46 and 47 Kidushin 28 The basic differences between Rashi , Tosphot, and the Rambam concerning exchange. To Rashi, there are only two categories: vessels or movable objects. There is no separate category of fruit. Thus, to Rav Nachman only vessels can cause acquisition by exchange or be acquired by exchange. To Rav Sheshet all movables can cause exchange, and be acquired by exchange. To Tosphot there are three categories: vessels, movables, and fruit. Vessels can cause exchange and be acquired by exchange. Movables can be acquired by exchange, but not cause exchange. (This is similar to how Rav Shach explains the Ravad) He holds that in exchange, neither object causes the acquisition. Rather, when one person picks up his object, then that is his.) When the other picks up his object, then that is his. To Tosphot fruit cannot be acquired nor cause acquisition by exchange, however when they are exchanged equal for equal, then they can be acquired by exchange and cause exchange [Tosphot Bava Mezia 47]. This is all very different from the Rambam who hold there are two kinds of exchange: equal for equal, or handkerchief. To the Rambam even fruit can be acquired by exchange. All movables can cause exchange when exchanged for other movables. But vessels alone can be used as acquisition by means of a handkerchief.​-------------------------------------------------------------------Bava Mezia 46 and 47 Kidushin 28 The basic differences between Rashi , Tosphot, and the Rambam concerning exchange. To Rashi, there are only two categories: vessels or movable objects. There is no separate category of fruit. Thus, to Rav Nachman only vessels can cause acquisition by exchange or be acquired by exchange. To Rav Sheshet all movables can cause exchange, and be acquired by exchange. To Tosphot there are three categories: vessels, movables, and fruit. Vessels can cause exchange and be acquired by exchange. Movables can be acquired by exchange, but not cause exchange. (This is similar to how Rav Shach explains the Ravad) He holds that in exchange, neither object causes the acquisition. Rather, when one person picks up his object, then that is his.) When the other picks up his object, then that is his. To Tosphot fruit cannot be acquired nor cause acquisition by exchange, however when they are exchanged equal for equal, then they can be acquired by exchange and cause exchange [Tosphot Bava Mezia 47]. This is all very different from the Rambam who hold there are two kinds of exchange: equal for equal, or handkerchief. To the Rambam even fruit can be acquired by exchange. All movables can cause exchange when exchanged for other movables. But vessels alone can be used as acquisition by means of a handkerchief.