(Mishnah): Partners that separated Terumah consecutively, R. Akiva says that they are both Terumah. (Since one partner cannot separate on behalf of the other without his consent, each only took Terumah for his own half, but both Terumos are valid.) The Chachamim say that only the first one is Terumah.

(R. Yosi): If the first one gave the required amount of Terumah, the second one is not Terumah. If not, the second one is Terumah.

When is this the case (that R. Akiva disagreed earlier, saying that the Terumah of both partners is Terumah)? When the first partner didn't speak (and give consent to the other); but if he authorized a member of his household, or his slave, or his maidservant (and certainly his partner) to separate Terumah, their separating is valid.

If he cancelled his authorization, if it was before the Terumah was separated, the Terumah is invalid; if it was only afterwards the Terumah is valid.

Workers don't have permission to separate Terumah, aside from those who press grapes, in order that they remove the Terumah before the grapes contract Tumah.

(Gemara): What's the case (of the partners)? If they are expert in separating Terumah, even R. Akiva agrees. If not, even the Rabbanan agree. The case is where they are regular people - R. Akiva assumes they are not experts and Rabbanan assume that they are experts.

According to R. Akiva, the Se'ah of the first one is half Terumah and half Tevel. The Se'ah of the second one is half Terumah and half Tevel in that in needs its Ma'asros taken.

Certainly the half Se'ah of the second partner is fixed by the separating of the first one. The question is whether the second half of the first Terumah is exempted through the separating of the second...

Answer: Ariston brought fruits and unknowingly left some of them in this sack. He then went and separated Terumah for the fruit that he had taken out. The question came before R. Yosi (as to whether his separation also covered the fruits that remained in the sack) and he said that his intention was for all the fruit.

(In the Mishnah, R. Yosi said that if the first one gave the required amount of Terumah, the second one is not Terumah. If not, the second one is Terumah.) Was he referring to the required amount of the Torah (which is 1/40th for a generous person, 1/50th for an average person and 1/60th for a stingy person) or to the amount that the other person usually gives?

If it's the Torah amount, R. Yosi agrees with the Rabbanan (and is merely explaining them. If it's that person's usually amount, R. Yosi disagrees with the Rabbanan.