This is not difficult for me (Abaye). I say that Heter joins with Isur (but not when the majority is Heter). The case is, there is more than one Se'ah of Chulin. (Even if the Terumah fell into the Chulin, the majority is Chulin.)

But if the Torah forbids a k'Zayis bi'Chedei Achilas Pras, this is even if the majority is Chulin!

Answer (Rav Dimi): The Beraisa discusses nowadays, that Terumah is only mid'Rabanan. Therefore, we are lenient.

Question (Abaye): Why do you say that "Mishras" teaches that Heter joins with Isur? Perhaps it comes only to forbid Ta'am k'Ikar (a food that absorbed the taste of Isur, like in the coming Beraisa)!

Question: Abaye asked all the above questions, to prove that Heter joins with Isur regarding all Isurim. Why does he now suggest that even regarding Nazir, it does not join?!

Answer: Abaye accepted Rav Dimi's answers. He then asked that even regarding Nazir, perhaps we forbid only Ta'am k'Ikar!

(Beraisa): "Mishras" forbids Ta'am k'Ikar. If one soaked grapes in water, and the water has a taste of wine, a Nazir is liable for drinking it. We learn from here to all Isurim.

Isurei Nazir are not permanent, they do not forbid all benefit, and there is a Heter for the Isurim (a Chacham can permit Nezirus. Alternatively, it is permitted to become a Nazir.) Still, the Torah forbids Ta'am k'Ikar;

Kilayim (crossbreeds) in a vineyard are permanently forbidden, all benefit is forbidden, and the Isur cannot be permitted. All the more so, the Torah forbids Ta'am k'Ikar!

Orlah (fruits of a tree before its fourth year) are likewise more severe than Isurei Nazir in two of these three ways. (However, the fruits do become permitted, i.e. what grows after three years. Alternatively, one can permit fourth-year fruits (outside Yerushalayim, or b'Tum'ah) through redemption. Alternatively, it is permitted to (plant trees and) create the Isur). All the more so, Ta'am k'Ikar is forbidden!

Answer: R. Avahu said that R. Akiva learns from "Mishras" that Heter joins with Isur. (The Tana of this Beraisa disagrees.)

Question: Where did R. Avahu learn that R. Akiva says so?

Answer #1 (Mishnah - R. Akiva): Even if he soaked his bread in wine, and there is enough to join to a k'Zayis, he is liable.

Rejection: Perhaps he is liable only if there is a k'Zayis of wine!

Question: If so, what is the Chidush?

Answer: He teaches that one is liable for a k'Zayis. The first Tana obligates only for a Revi'is.

Answer #2 (Beraisa - R. Akiva): If a Nazir soaked his bread in wine and ate a k'Zayis of bread and wine, he is liable.

Question (Rav Acha brei d'Rav Avi): Since R. Akiva uses "Mishras" to teach that Heter joins with Isur, what is his source to forbid Ta'am k'Ikar?

Answer #1 (Rav Ashi): He learns from meat and milk:

The meat absorbs only a taste of milk (or vice-versa), and it is forbidden. We learn to all cases!

Chachamim say that we cannot learn from meat and milk, because it is exceptional.

Question: What is exceptional about meat and milk?

Suggestion: Each is permitted by itself, but together they are forbidden.

Rejection: This is not exceptional. The same applies to Kilayim (mixing seeds of (or grafting) diverse species of vegetation, working with or crossbreeding different species of animals, and wearing a garment of wool and linen)!

Answer: If one soaks them together they are permitted (even if they absorb taste from each other), but if they are cooked together, they are forbidden.

Rejection: For this reason, also R. Akiva should not learn from meat and milk!

Answer #2 (Rav Ashi): He learns from absorbed tastes in Kelim of Nochrim:

"Whatever Kelim are used with fire (must be Kashered before usage)" teaches that absorbed tastes in Kelim of Nochrim are forbidden.

Even though it is merely taste, it is forbidden. We learn from this to all cases!

Question (Rav Acha): Why don't Chachamim learn from this?

Answer (Rav Ashi): It is exceptional:

Normally, detrimental tastes are permitted. Detrimental tastes absorbed in Kelim of Nochrim are forbidden.

Question: Since it is exceptional, why does R. Akiva learn from it?

Answer (Rav Huna bar Chiya): The Torah forbids only a Kli used in the last 24 hours, and the absorbed taste is not detrimental;

Chachamim say that even within 24 hours, the absorbed taste is slightly detrimental.

Question (Rav Acha): We should learn from Chachamim to R. Akiva!

Chachamim expound "Mishras" to forbid Ta'am k'Ikar regarding Nezirus, and they learn to all Isurim.

R. Akiva expounds "Mishras" to teach that Heter joins with Isur regarding Nezirus. He should also learn to all Isurim!

Answer (Rav Ashi): The Torah taught that Heter joins with Isur in two cases, Nezirus and Chatas. Shnei Kesuvim (a principle the Torah taught twice, and one of them could have been learned from the other) do not teach to other cases.

We already discussed Nazir. The case of a Chatas is as follows:

(Beraisa) Suggestion: Perhaps "any (food) that touches its (a Chatas') meat will become Kodesh" applies even if the food did not absorb!

Rejection: "In its meat" teaches that it is forbidden only if it absorbed.

"Yikdash (it becomes Kodesh)" like the Chatas. If the Chatas was Pasul (and may not be eaten), the food may not be eaten. If the Chatas was Kosher, the food may be eaten with the stringencies of the Chatas (that day, in the Mikdash, by Kohanim. This teaches that Ta'am k'Ikar. However, we already learned Ta'am k'Ikar from absorptions in Kelim of Nochrim, so Chatas teaches that Heter joins to Isur.)

Chachamim hold that we could not learned Chatas from Nazir or vice-versa (therefore, we cannot learn from it that Heter joins to Isur, and we learn Ta'am k'Ikar to elsewhere):

Nezirus is Chulin, therefore we cannot learn it from Chatas, which is Kodshim;

We cannot learn Chatas from Nezirus, because the Torah is extra stringent about Nezirus, and forbids even Chartzanim.

R. Akiva agrees that we cannot learn Chulin from Kodshim.

However, he holds that we could have learned Chatas from Nazir, just like we learn in general from Nazir.

Retraction: Chachamim agree that (we could have learned Chatas from Nazir, therefore) Chatas teaches that Heter joins with Isur. We cannot learn from Kodshim to Chulin (that Heter joins with Isur);

We learn Ta'am k'Ikar from Nazir ("Mishras") to all cases.

R. Akiva says that both teach that Heter joins with Isur. Since this was taught in two places, we do not learn to other cases.

Question (Rav Ashi - Beraisa): "From all that comes from the grapevine" teaches that Isurei Nazir join.

According to R. Akiva, even Heter joins with Isur, all the more so, forbidden foods join!

Answer (Rav Kahana): Heter joins with Isur only when they are eaten together. Forbidden foods join even when eaten one after the other.