Fifteen women release their co-wives, and their co-wives' co-wives, from chalitzah and from yibum, ad infinitum. They are the follow- ing: A [man's] daughter, daughter's daughter, and son's daughter; his wife's daughter, her son's daughter, and her daughter's daughter; his mother-in-law, mother-in-law's mother, and father-in-law's mother; his maternal sister, mother's sister, wife's sister, maternal brother's wife, the wife of his noncontemporaneous brother, and his daughter-in-law. These release their co-wives and their co-wives' co-wives from chalitzah and from yibum, ad infinitum.  If any of these died, refused, was divorced, or was found to be an ailonis, their co-wives are permitted. [However,] one cannot say of his mother-in-law, or mother-in-law's mother, or father-in-law's mother, that they were found to be an ailonis or that they refused.

How do they release their co-wives? [If] a [man's] daughter, or [any] one of these forbidden relations, was married to his brother, and he had another wife [as well], and he died —- just as his daughter is released, so too is her co-wife. If his daughter's co-wife went and married his second brother, and he [also] had another wife, and [then] he died —- just as his daughter's co-wife is released, so too is her co-wife's co-wife, even if there are a hundred.  How is it that if they died their co-wives are permitted? [If] a [man's] daughter, or [any] one of these forbidden relatives, was married to his brother, and he [also] had another wife, and his daughter died, or was divorced, and then his brother died —- her co-wife is permitted.  Anyone who was able to refuse but did not do so —- her co-wife requires chalitzah but is prohibited from yibum.