1)

(a)We think that if the author of the Mishnah ('ha'Omer l'Ishah Harei At Mekudeshes Li l'Achar she'Esgayer ... ') is Rebbi Akiva, then in the last case there ('le'Achar she'Yachlotz Yevamech'), the Kidushin would be valid - because Rebbi Akiva holds 'Adam Makneh Davar she'Lo Ba Le'olam'.

(b)The Tana Kama in the Mishnah in Nedarim states that if a woman says to her husband 'Konam she'Ani Osah l'Picha, Ein Tzarich Lehafer' - because she does not have the authority to deprive him of his rights, and her Neder is therefore not effective.

(c)Rebbi Akiva says that he is obligated to nullify the Neder, in case she produces in excess of her obligation, and on that excess, her Neder does take effect.

(d)We initially think that Rebbi Akiva must hold 'Adam Makneh Davar she'Lo Ba l'Olam', but then quote Rav Huna b'brei d'Rav Yehoshua - who establishes Rebbi Akiva when she designates her hands for whatever she produces, and her hands are already in the world.

2)

(a)Rav Nachman bar Yitzchak disagrees with Rav Huna b'rei d'Rav Yehoshua. In his opinion - Rav Huna, Rav, Rebbi Yanai, Rebbi Chiya, Rebbi, Rebbi Meir, Rebbi Eliezer ben Yakov and Rebbi Akiva all hold 'Makneh Davar she'Lo Ba Le'olam'.

(b)Rav Huna says that someone who sells the fruit of a date-palm in winter, before it has grown - can retract from the sale only until such time as the fruit has grown (up to a certain stage of growth - as we will explain shortly), but the moment it reaches that stage, he may no longer retract (because the initial transaction becomes valid retroactively.

(c)According to Rav Nachman, he can retract even in Nisan, after the fruit has grown. He concedes to Rav Huna however - that the seller cannot reclaim what the purchaser has already eaten.

(d)Rav Huna learned this ruling from Rav, whom he quotes as saying that if someone sells a field before having purchased it himself - the transaction is valid.

3)

(a)Rebbi Yanai learned this ruling from Rebbi Chiya, who gave his consent to what Rebbi Yanai, who took Ma'aser one Friday from the fruit in his house, to exempt a basket of fruit that he knew his share-cropper would bring him, but who was late that day in bringing it.

(b)Rebbi Chiya learned from the Pasuk in Re'eh "Lema'an Tilmad l'Yir'ah es Hash-m" (written in connection with Terumos and Ma'asros) - that one is permitted to Ma'aser even something that he does yet have (and which is considered a 'Davar she'Lo Ba Le'olam' - see Tosfos DH 'Maysi') "Kol ha'Yamim" - is a hint to Shabbos and Yom Tov.

(c)The Pasuk cannot be coming to permit the separation of Terumos and Ma'asros on Shabbos itself - because the prohibition of separating Terumos and Ma'asros on Shabbos and Yom Tov is only mid'Rabanan (as the Mishnah in Beitzah teaches us), and we do not require a Pasuk to permit Isurim d'Rabanan.

(d)The reason for that is - because it does entail any Melachah, only 'Tiltul' (moving things that are at worst, Muktzah).

4)

(a)Rebbi Yanai believed that he had done the wrong thing - because the previous night, he had dreamt of a Pasuk "Kanah Ratzutz", which he thought referred to a Pasuk in Melachim, which has negative connotations. The 'Kanah Ratzutz' on which Yisrael were being accused of relying was - Paroh King of Egypt.

(b)Rebbi Chiya reassured him however, that he had nothing to worry about - since it might just as well refer to a Pasuk in Yeshayah, "Kanah Ratzutz Lo Yishbor ... " which concludes "l'Emes Yotzi Mishpat" (implying that Rebbi Yanai did the right thing).

5)

(a)Rebbi too, holds 'Adam Makneh Davar she'Lo Ba Le'olam'. He explains the Pasuk "Lo Sasgir Eved el Adonav" - to mean that someone who purchases an Eved in order to set him free is obligated to do so (even though when he made the condition, he did not yet own him, and it is a Davar she'Lo Ba Le'olam, as Rav Nachman bar Yitzchak explains).

(b)And so do Rebbi Meir, Rebbi Eliezer ben Yakov and Rebbi Akiva. Rebbi ...

1. ... Meir in the Mishnah that we quoted on the previous Daf ('ha'Omer l'Ishah Harei At Mekudeshes Li l'Achar she'Esgayer, l'Achar she'Tisgayri ... Einah Mekudeshes') - Meir rules 'Mekudeshes'.

2. ... Eliezer ben Yakov rules in a Beraisa about someone who designates Terumah from a row of detached fruit to cover a row of fruit that is still attached, or vice-versa - that his Terumah is valid as soon as it has grown a third and has been detached.

(c)We learn from the Pasuk "v'Asas es ha'Tevu'ah li'Shelosh ha'Shanim" - that fruit that has grown one third is considered ready, regarding Terumos and Ma'asros (as if the Torah had written not, "li'Shelosh ha'Shanim", but "li'Shelish ha'Shanim" - meaning a third of what it grows in other years).

6)

(a)They asked Rav Sheshes whether one witness is believed to permit a woman to perform Yibum. It is obvious that, if the (main - see Tosfos DH 'Eid') reason of our Tana, who believes the witness with regard to allowing her to get married, is because a person does not lie in any matter which is destined to become exposed anyway, then the same will apply when it comes to allowing her to perform Yibum. The other possible reason for the Tana to believing one witness is - because knowing what lies in store for her should her husband still be alive, the woman will make extensive inquiries before remarrying.

(b)This reason might not apply when it comes to allowing her to perform Yibum however - before we are afraid that, perhaps, out of love for the Yavam (whom she knows well), she will ignore all other considerations.

(c)Rav Sheshes replied with our Mishnah 'Amru Lah Mes Bnech v'Achar Kach Mes Ba'alech v'Nisyabmah, v'Achar-Kach Amru Lah ... '. Assuming that the Mishnah is speaking about two witnesses who overrule the testimony of the one witness who preceded them, he infers that - had the second pair of witnesses not testified, the first witness would have been believed to permit the woman to perform Yibum (resolving the She'eilah that he was asked).

(d)The Tana cannot be talking about a case where the two witnesses came first (and not one) - because then a. why would we rely on the second pair of witnesses rather than the first? and b. why would the Tana then call the children Mamzerim, when in fact, they would only be Safek Mamzerim?