46a Rav Ashi's answer

As we saw today, Rav Ashi differs with Ula's answer in that the coin provided by the shulchani is a real matbeia, yet there is no problem of chalipin with tiv'a due to the fact that he has money at home (based on tosfos understanding of the sugya). Acc to Rav Ashi, though, why does the money returned by the purchaser (the guy paying his workers) have to be non minted coins (it seems acc to Rashi that this is not the case)? As we said in shiur, since you are "purchasing" maos for the dinar, why cant we understand that he is paying back with real money as well?

Based on maharsha in an earlier tosfos, perhaps the answer is that this allows us to learn the sugya even acc to man d'amar that אין מטבע נקנה בחליפין
Perhaps, Tosfos is telling us that money for money, even if the money is different amounts would still involve se'a be'sa and would not be considered a sale of money? The language used in tosfos , though, calls this a matbea and not an unminted coin, which seems to not be what Rav Ashi answers.

אמר שמואל לא נטל נטל ממש (Bava Metzia 44a)

Rashi understands that the Gemara's answer is that he is a שואל on the whole barrel and therefore חייב. Most of the other Rishonim (on the Gemara מ"א.) learn a different p'shat that since he wants the רביעית to stay in the barrel because it stays best there, we look at it as if he took the רביעית of wine out and put it back and therefore he was מחסר. In other words it is שליחות יד with a חסרון.

The ראב"ד has a tremendous chiddush here (הל' גזילה ג:י"ב) that if you are שולח יד on only part of the object you are only חייב on that part, (the ריטב"א is מדייק from Rashi here that he holds this way as well). The only time you are חייב for שליחות יד on the whole object is if your כוונא is to steal the whole object. The obvious question is that this is against the Gemara on מ"א: both by הניח מקלו ותרמילו where you are clearly only שולח יד on part of the animal (your כוונא is definitely not to steal the whole animal but to use it and be מחסר a little) and by ר' יעקב בר אבא. You see that if you have כוונא to steal the whole object then you are חייב even without a חסרון according to everyone, yet according to the Raavad this is exactly the case where there is a מח' whether שליחות יד צריכה חסרון or שליחות יד אינה צריכה חסרון. Additionally, if the only time you are חייב for שליחות יד on the whole object is if your כוונא is to steal the whole object, what exactly is the חידוש of שליחות יד? You are a גזלן anyway? This would seem to be why all the other Rishonim argue on the Raavad.

בעי ר' אשי הגביה ארנקי (Bava Metzia 44a)

The Gemara says that Shmuel could even be according to those who hold that שליחות יד צריכה חסרון and this case is different because he wants the רביעית of wine in the barrel so that it stays better. R' Ashi then asks what about ארנקי? The simple understanding of the Gemara is that R' Ashi's whole question is only if שליחות יד צריכה חסרון but if שליחות יד אינה צריכה חסרון then the case of ארנקי is a classic case of שליחות יד (since at the time he is מגביה he has כוונה to be מחסר by taking out a דינר) and he is for sure חייב. In fact, this is the way the Rif, Rosh and Tur pasken. However, the Rambam (הל' גזילה ג:י"ב) even though he paskens that שליחות יד אינה צריכה חסרון brings down the case of R' Ashi as a ספק how to pasken. We see from the Rambam that he held that R' Ashi's question was even if you hold שליחות יד אינה צריכה חסרון. The Acharonim work hard to understand how the Rambam could say this.

(ר' עקיבא אומר כשעת התביעה (בבא מציעא מ"ג

What case is ר' עקיבא talking about? Is ר' עקיבא talking about the same case as ב"ה and ב"ש, namely שבח?

Tosafos says it can't be. Tosafos asks, if ר' עקיבא holds that שינוי קונה then he was קונה the שבח and he should keep it, if he holds that שינוי אינו קונה then he should pay for what grows even after the תביעה. Therefore Tosafos says that ר' עקיבא is talking about where the price of the object goes up. ר' עקיבא holds that even though כל הגזלנים משלמים כשעת הגזילה a שולח יד is different and pays the value of the object כשעת התביעה even if it goes down which is a tremendous chiddush.

The בעל המאור learns that ר' עקיבא is also going on the same case as ב"ה and ב"ש (namely שבח). He explains that ר' עקיבא holds that he doesn't get the קניני גזילה to be קונה the שבח until the time of the תביעה and therefore that is the time that is קובע. In other words, any שבח until the time of the תביעה belongs to the נגזל. This answers Tosafos's objection, ר' עקיבא holds שינוי קונה but only from the time of תביעה because that is when he gets the קניני גזילה.

The Rif says the opposite of the בעל המאור. The Rif says that any שבח that the גזלן takes from the animal is his until the תביעה, after the תביעה the שבח belongs to the נגזל.