Study Yevamot folio 29B with parallel Hebrew-English text, traditional commentary, and modern study tools. Free access to Babylonian Talmud online.
And if it enters your mind that according to Beit Shammai levirate betrothal acquires the woman as a full-fledged acquisition, then this matter could potentially have been resolved ab initio: This brother should perform levirate betrothal and acquire one sister, and that brother should perform levi
The Talmud objects: Rather, what then? If levirate betrothal does not serve to fully acquire the woman, what is the alternative? It must be that according to Beit Shammai levirate betrothal precludes the rival wife from entering levirate marriage with a complete preclusion. If so, there is an addit
Rather, what have you to say? One must assert that levirate betrothal performed in circumstances where it is permitted to perform levirate marriage, i.e. where there is no prohibition with regard to the close relative of a woman with whom the yavam has a levirate bond, completely precludes the riva
Rav Ashi teaches this discourse in this manner: R' Elazar said: Do not say that according to Beit Shammai levirate betrothal precludes entering levirate marriage as a complete preclusion, so that the rival wife of the woman who received levirate betrothal does not require even ḥalitza. Rather, it p
R' Avin said: We, too, learn this statement from the Mishnah, where it states: Beit Shammai say: They may maintain them as their wives. From here it can be deduced: Yes, they may maintain them as their wives after the fact; no, they are not allowed to marry them ab initio. And if it enters your mi