(Mishnah): If two brothers Chereshim were married to two sisters Chereshos, or two sisters Pikchos, or two sisters, one Chereshes and one Pikachas, or two sisters Chereshos were married to two brothers Pikchin, or two brothers Chereshim, or two brothers, one Cheresh and one Pike'ach [and one man died], they are (i.e. in every case, the widow is) exempt from Chalitzah and Yibum;

If the wives were unrelated, the Yavam may do Yibum. Afterwards, if he wants he may divorce her.

If two brothers, one deaf and one Pike'ach, were married to two sisters Pikchos, and the deaf brother died, his wife is exempt from Chalitzah and Yibum, for she is (mid'Oraisa the Yavam's) Achos Ishto;

If the Pike'ach died, the Cheresh must divorce his wife, and the Yevamah is forbidden forever (until the Yavam dies).

(Gemara - R. Yochanan): A case was omitted from the Reisha. [A case similar to the omission] is taught in the Seifa (Mishnah 5).

Question: What [other case] should have been taught in the Reisha?

Answer: When a Cheresh was married to a Pikachas, and [his brother, a] Pike'ach was married to a Chereshes (her sister. Since both marriages are mid'Rabanan, also in this case they are exempt);

However, if the Pike'ach was the Pikachas' husband, and the Cheresh was the Chereshes' husband (one marriage is mid'Rabanan and one is mid'Oraisa, so they are not exempt;) this is what was taught after the Seifa below (Halachah 5. We explained this like SEFER NIR. He suggests that the case was omitted, because when the women are not sisters, our Mishnah says that he does Yibum, i.e. for Chereshim cannot do Chalitzah. This is not true when a Pikachas fell to Yibum to a Pike'ach.)

Question: What is the law of her Tzarah [of a Pikachas married to a Cheresh; she is Achos Ishto of the Yavam? Is she exempt like a regular Tzaras Ervah, even though her marriage is only mid'Rabanan?]

Answer: We learn from the following. If his daughter, a Pikachas, was married to his brother, a Cheresh, her Tzarah is exempt from Chalitzah or Yibum.

(Mishnah): If two brothers Pikchim were married to two sisters, one deaf and one Pikachas, and the husband of the Chereshes died, she is exempt from Chalitzah and Yibum, due to Achos Ishto;

If the husband of the Pikachas died, the Yavam must divorce his wife, and the Yevamah does Chalitzah.

Question: What is the law of her Tzarah [of a Chereshes married to a Pike'ach]?

Answer: We learn from the following. If his daughter, a Chereshes, was married to his brother, a Pike'ach, her Tzarah does Chalitzah and not Yibum. (Since the Ervah is a Chereshes (normally, her marriage is only mid'Rabanan), her Tzarah does not look like Tzaras Ervah. In Halachah 3, the Ervah is a Pikachas. Her Tzarah looks like Tzaras Ervah - PNEI MOSHE.)

Note: When she does not look like Tzaras Ervah, we require Chalitzah, lest people say that a Yevamah leaves without Chalitzah or Yibum. When the Tzarah looks like Tzaras Ervah, there is no need for Chalitzah. Further, if she would do Chalitzah, people might say that Tzaras Ervah needs Chalitzah or Yibum, and they will come to do Yibum! (PF)

(Mishnah): If a Cheresh was married to a Chereshes, and his Pike'ach brother was married to her Pikachas sister, and the Cheresh died, his wife is exempt from Chalitzah and Yibum, due to Achos Ishto;

If the Pike'ach died, the Cheresh must divorce his wife, and the Yevamah is forbidden forever (until the Yavam dies).

Question: What is the law of her Tzarah [of a Chereshes married to a Cheresh]?

Answer: We learn from the following. If his daughter, a Chereshes, was married to his brother, a Cheresh, her Tzarah is exempt from Chalitzah or Yibum. (Since Zikah of both widows is equal (they fall from a Cheresh), she looks like Tzaras Ervah. - PNEI MOSHE)

(Mishnah): If two brothers, one deaf and one Pike'ach, were married to two unrelated Pikchos, and the Cheresh died, the Yavam may do Chalitzah or Yibum.

If the Pike'ach died, the Yavam does Yibum and can never divorce her.

(Gemara) Question: [A Pikachas who fell to Yibum from a Cheresh to a Pike'ach,] may she eat Terumah?

Answer: We learn from the following. If a Bas Yisrael Pikachas married a Kohen Cheresh, she does not eat Terumah. If she fell to a Yavam - if he is a Pike'ach, she eats. If he is a Cheresh, she does not eat.

(Mishnah): If two brothers Pikchim were married to two unrelated women, one Pikachas and one Chereshes, and the husband of the Chereshes died, the Yavam does Yibum. [Later,] he may divorce her if he wants.

If the Pike'ach husband of the Pikachas died, the Yavam may do Chalitzah or Yibum.

If a Cheresh was married to a Chereshes, and his Pike'ach brother was married to a Pikachas not related to the Chereshes, and the Cheresh died, his wife does Yibum. The Yavam may divorce her if he wants;

If the Pike'ach died, the Yavam does Yibum, and he can never divorce her.

(Gemara) Question: [A Pikachas who fell to Yibum from a Pike'ach to a Cheresh,] may she eat Terumah?

Answer: We learn from the following. If a Bas Yisrael Pikachas became Mekudeshes to a Kohen Pike'ach, and before Chupah he became a Cheresh or she became a Cheresh, she does not eat Terumah;

If he died and she fell to a Yavam, even if he is Cheresh, she eats. If he is a Cheresh, she does not eat. In this, the Yavam has greater power than the husband, for a Yavam Cheresh feeds, and a husband Cheresh does not feed.