The Tana of Litra Ketzi'os holds that even a d'Rabanan is not Batel, and certainly not a Tereifah.

R. Meir taught the Machlokes R. Eliezer and R. Yehoshua:

(R. Eliezer) We view the upper part of the barrels as separate from the lower part, adding up to 101 for Bitul.

(R. Yehoshua): There need to be 100 Kelim of Chulin to be Mevatel the one with Terumah.

R. Yehudah taught the Machlokes differently:

(R. Eliezer): There need to be 100 barrel openings for Bitul (but the bottoms are Kosher).

(R. Yehoshua): There can be no Bitul since the openings are sold by number (even though we are dealing with Terumah d'Rabanan).

All agree that there is Bitul if the Litra Ketzi'os is packed into an unknown Igul.

Question: But that is the very question at hand!?

Answer (R. Papa): We mean that it is in an unknown part of the Igul.

(R. Ashi): The Safek regarding the egg is indeed a Safek d'Rabanan (Safek Yom Tov Safek Chol), but it is a Davar she'Yesh Lo Matirin which is never Batel.

(Acheirim citing R. Eliezer): An egg and its mother may be eaten.

Question: What type of chicken are we speaking of?

Answer: A chicken designated to be eaten.

Question: Then it is obvious (R. Eliezer would not need to teach us that Beis Shamai permits the chicken - he need only have mentioned the egg)!?

Answer: It is a chicken designated for laying eggs.

Question: Then both the chicken and eggs are Asurim (R. Eliezer disagrees with Beis Shamai and he holds of Muktzah)!?

Answer (R. Zeira): R. Eliezer means that an egg laid on Yom Tov may be eaten along with the chicken.

Question: Under what circumstances would this be the case?

Answer (Abaye): In a case of an undesignated chicken whose designation is discovered retro- actively (he either slaughters it thus demonstrat- ing that it was for eating, permitting its egg, or he leaves the chicken which then remains Muktzah).

Answer (R. Mari): The chicken was always designated for eating and R. Eliezer mentioned the chicken for emphasis (Guzma) in his dispute with Beis Hillel.

This can be demonstrated from the additional phrase of R. Eliezer's cited by Acherim that not only can the egg and chicken be eaten, but also the chick and its shell.

Question: What is meant by its shell!?

Answer: It means its shell, literally.

Question: But a shell is not edible!?

Answer: It means the chick while still in its shell.

Question: But even the most lenient position (Rabanan who argue with R. Eliezer b. Yakov) only permit a chick once it has hatched!?

Answer: A chick and its shell is a Guzma, as is the expression it and its mother.

(Rav): An egg laid on one is prohibited on the other.

(R. Yochanan): It is permitted on the other.

Question: Is Rav contradicting himself and holding that the two days are Kedushah Achas!?

Rav ruled like the four elders (an Eruv may be set for Shabbos and separately for its neighboring Yom Tov).

These elders follow the view (of R. Eliezer) that Shabbos and Yom Tov are Shtei Kedushos.

Answer: Rav and R. Yochanan are arguing over Hachanah (Rav subscribes to Hachanah d'Rabah and prohibits the egg which was prepared on a Yom Kodesh while R. Yochanan permits it).

This echoes the Machlokes Tanaim.

(Tana Kama): The egg laid on Shabbos is permitted on Yom Tov, and the reverse.

(R. Yehudah citing R. Eliezer): Such an egg is also subject to the Machlokes Beis Hillel and Beis Shamai.

R. Ada b. Ahavah was asked if eggs laid on Yom Tov may be prepared for Shabbos or if they are Muktzah.

R. Ada inferred that the questioner (correctly) assumed that the eggs would be permitted on Shabbos (like R. Yochanan), and his only question was regarding their Muktzah status on Yom Tov.

He ruled that, still, they are Muktzah (and only permitted on Shabbos, as in the cited Beraisa).

R. Papa was asked on Shabbos whether eggs laid that day would be permitted tomorrow on Yom Tov, and he asked the petitioner to return the next day.

He put off his ruling owing to his having drunk wine.

R. Papa was pleased that he had not jumped to rule, in error, with the rule that the Halachah is like R. Yochanan.

In fact the Halachah is like Rav in three cases (this being one) and not like R. Yochanan.

(R. Yochanan): Such branches may not be burned on Yom Tov.

Question (R. Yochanan, rhetorically): Then why is the egg permitted!?

Answer: The fact that the egg (which could, in theory, be used on Shabbos) is prohibited on Shabbos signals that there is no Heter on Yom Tov for an egg laid that day.

However, the branches which fell on Shabbos are always prohibited and their use on Yom Tov may lead people to be lenient with branches which fell on Yom Tov itself.

(R. Masnah): If branches fell directly into the oven, one may be Mevatel them with other branches (so that the majority of the heat derives from permitted branches).

Question: But when he turns the coals, he will be moving Muktzah!?

Answer: The majority determines that he is moving Heter.

Question: But it is not permitted to be Mevatel Isur l'Chatchilah!?

Answer: That is only in a d'Oraisa.

Question: But the branches are a Davar she'Yesh Lo Matirin (recalling R. Ashi's teaching) and should never be Batel!?

Answer: That is only Isur b'En, not where it has been burnt to coals.

(Rav): An egg laid on the first day of Yom Tov is permitted on the second (Chutz la'Aretz-Ma Nafshach).

(R. Asi): It is prohibited.

Question: Is R. Asi contradicting himself, given that we know that he said Havdalah between one day of Yom Tov and the next (so he must not hold Kedushah Achas)!?

Answer: R. Asi conducted himself stringently (prohibiting the egg and also reciting Havdalah) out of doubt whether it is one Kedushah or two.

(R. Zeira): R. Asi seems to be correct, given our contemporary practice of making two days of Yom Tov even when our calendars are accurate.

(Abaye): Rav is correct (two Kedushos) given that we have two days only in the times and places which are plagued by Kusim.

Question: Then why, today, do we have two days?

Answer: Because R. Elazar ruled that those in Bavel should maintain this practice, lest the calendar again be lost due to oppression.