(Mishnah): If a man was married to two orphaned minors and he died, Bi'ah (Yibum) or Chalitzah of one of them exempts the other. The same applies if he was married to two Chershos (deaf-mute women).

If an orphaned minor and a Chereshes [fell to Yibum], Bi'ah of one does not exempt the other.

(Gemara): Like the Kinyan of this, so is the Kinyan of this. (Therefore, Yibum or Chalitzah of one of them exempts the other.)

Question: What does he do [in the Seifa]?

Answer (R. Chiya bar Ashi citing Rav): He enters the Chereshes and divorces her with a Get. The Ketanah waits until she matures, and does Chalitzah.

Question: She should do Chalitzah immediately!

Answer: She cannot, due to R. Meir;

R. Meir says that one may not do Chalitzah or Yibum to a Ketanah, lest she be found to be an Ailonis.

If he had Bi'ah with the Ketanah, he divorces her with a Get, and the Chereshes is forbidden forever.

If he transgressed and had Bi'ah with the Chereshes, he divorces her with a Get, and she is permitted [l'Shuk].

(R. Heila): [Normally, Bi'ah Pesulah does not exempt Zikah. Here it does,] for her Tikun.

Question (R. Bun bar Chiyah, to R. Heila): What is 'for her Tikun'? (She has a better solution!)

Just like you say there (the Reisha of our Mishnah, if one was married to two Ketanos, and he died, the Yavam) does Chalitzah to the side acquired in one, and exempts her Tzarah - also here, he should do Chalitzah to the side acquired in the minor, and enter the Chereshes!

Answer (R. Heila citing Reish Lakish): We do not find two Yevamos [from one house], that one does Chalitzah and one does Yibum.

Question: Do we find two Yevamos, that one does Chalitzah and one leaves with a Get?!

Answer (R. Heila): Yes - a Mishnah teaches that if he gave a Ma'amar to this one and did Chalitzah to this one, the first needs a Get.

(Mishnah): If a Pikachas (healthy woman) and a Chereshes [fell to Yibum], Bi'ah (Yibum) of the Pikachas exempts the Chereshes, but Bi'ah of the Chereshes does not exempt the Pikachas.

(Gemara): If a Pikachas and a Chereshes [fell to Yibum], Bi'ah of the Pikachas exempts the Chereshes, but Bi'ah of the Chereshes does not exempt the Pikachas, rather, it disqualifies the Pikachas.

(Mishnah): If an adult and an [orphaned] minor [fell to Yibum], Bi'ah of the adult exempts the minor, but Bi'ah of the minor does not exempt the adult.

(Gemara): If an adult and a minor [fell to Yibum], Bi'ah of the adult exempts the minor, but Bi'ah of the minor does not exempt the adult, rather, it disqualifies the adult.