Bava Batra 50: Usufruct Property and Protest

The Gemara attempts to differentiate the current assertion - that a woman can void the sale of her field even if she previously consented in certain situations - from other rulings that suggest that such a sale is always valid.  There are a number of statements describing the use of usufruct property, the property that belongs to a woman because she brought it into her marriage.   

Other comparisons are introduced as well.  For example, one might sell his Canaanite slave with the condition that the sale will serve the seller for thirty days before the transfer.   In this case, for those thirty days the slave benefits the seller with his work but actually belongs to the buyer.  Rabbi Meir had held that ownership of profits is like ownership of the item itself.  Rabbi Yehuda suggests that the second owner already owns the slave because he is not "his money".  Rabbi Yosei claims that both sellers have ownership.  Rabbi Elazar argues that neither owner has true ownership.  

Our Mishna had taught that a man does not have the ability to establish chazaka regarding his wife's property.  Rav questions whether or not a married woman must protest in a case where her husband tries to sell her property.  However, it is different to protest one's husband's desires.  Perhaps this is a case where the husband already dug pits, ditches and caves in her property, behaving in a way that establishes his ownership already.  Is chazaka valid when it is based on damage to another's property?   Only if there is no immediate protest by the owner.  

Rav Yosef suggests that when a woman protests against a man who is not her husband; this man had profited from her field for almost enough time to establish chazaka before and then after her husband's death. This is an example of a migo, for he could have said that he bought the field from her and possessed it for three years.  He also could have said that her husband sold the field to him.