(Mishnah): Terumah, Terumas Ma'aser of Demai, Chalah and Bikurim, they are Batel in 101 (if they were mixed with at least 100 times their own volume, Min b'Mino), and they join with each other, and [when they are Batel] one must remove [their amount from the mixture and give it to a Kohen].

Orlah and Kil'ai ha'Kerem, they are Batel in 201, and they join with each other, and one need not remove from the mixture.

R. Shimon says, they do not join [to forbid Min b'Mino in less than 201, and not to gives taste Min b'Eino Mino. The first Tana holds that they join in both ways.]

R. Li'ezer says, they join to give taste, but not to forbid [Min b'Mino in less than 201].

(Gemara - Mishnah): Terumah, Terumas Ma'aser...

According to whom was this needed? It is according to R. Shimon;

Even though R. Shimon says that two Shemos (different Isurim) do not join, he agrees that all of these [that are called] Terumah, they join.

Question: Who taught Terumas Ma'aser of Demai?

Answer: It is R. Meir, for R. Meir is stringent about mid'Rabanan laws like Torah laws.

Question: Where do we find that R. Meir is stringent about mid'Rabanan laws like Torah laws?

Answer (R. Chaninah - Mishnah): A woman who sees a Kesem (blood on a garment), she is messed up (she does not know when she became Nidah), and she is concerned for Zivah (if the stain is the size of three Grisim (beans), and it is possible that a Gris came on each of three days of Zivah). R. Meir says so;

Chachamim say, Zivah does not apply to Kesamim.

Question (R. Yonah): Why did the Mishnah not teach Chalas Demai, like it taught Terumas Ma'aser of Demai?

Answer: Chalas Demai was not taught (one need not separate it, for Amei ha'Aretz were not suspected about it. We explained this like MEICHAL HA'MAYIM.)

(R. Chananyah citing Shmuel): Demai (if one bought a dough or loaf from an animal), it needs [a separation of] Chalah.

(R. Chiya bar Luliva, to R. Chananyah): He may take its value from the Shevet (since it is a Safek, he need not give it to a Kohen for free).

Support (R. Chananyah, to R. Chiya): So said Shmuel - he may take its value from the Shevet.

(R. Mana citing R. Yosi): He does not take its value from the Shevet. [If he could,] tomorrow he will bring Vadai, and say that it is Demai, in order to take its value from the Shevet!

Question (R. Yochanan, to Gamliel Zuga): Was it your custom to take Chalah from Demai?

Answer (Gamliel Zuga): Did not Shmuel the brother of R. Berachiyah say that at the time they decreed about Demai, most Amei ha'Aretz separated [Chalah] in their houses (so they did not decree about it)?

(R. Yosi bei R. Bun): (A Mishnah (Demai 5:1) says that when one buys from an Am ha'Aretz takes an amount for Terumas Ma'aser and Chalah, and declares them.) It is an enactment of Beis Din that the Chalah is in the north of the north (if he did not specify its place - GRA.)