Translation:Shulchan Aruch/Choshen Mishpat/142
Paragraph 1- Although one cannot gain a presumption in less than three years, if the possessor brings witnesses attesting that the objector lifted a basket of fruit from this field onto the possessor’s shoulder to assist him in bringing the fruits to his home, the possessor would obtain an immediate presumption. There are those who say that the same would apply if the possessor sent a gift to the objector from the fruits he was eating and the objector accepted them, and the possessor would obtain a presumption, because had the land actually belonged to the objector he would not have accepted it as a gift but would have taken everything. From this we can deduce that if Reuven and Shimon had a mutual objection on the other living on a dwelling, and Reuven acquired rights for a year to that dwelling, the dwelling belongs to Shimon because if Reuven really owned it he would not have purchased it from Shimon for a year. The same would apply to anything similar and the same would apply if Reuven rented it from Shimon, as discussed later in Siman 147. If the objector claims that the possessor only went down for the fruits which belonged to the possessor but he never sold the actual land, he would be believed and the possessor would not obtain a presumption. This is only true within three years, but if the objector claims after three years that the possessor only went down for fruits, we would not listen to him. Thus, if one does allow another to go down for fruits, he must protest within three years to show that he only went down for the fruits.
Paragraph 2- If the wall between Reuven and Shimon fell and Reuven erred and rebuilt the wall in Shimon’s property because he was unaware of where the original wall was, it would not create a presumption to enable him to take possession of the land he took from Shimon’s border. If Shimon assisted in the building and confessed that he knew Reuven was entering into his property, however, Reuven would obtain ownership, even though he was unaware, and he would immediately acquire the property of Shimon that he built into.
Paragraph 3- If Reuven opened a window into Shimon’s courtyard in his presence, there are those that say that he would not obtain a presumption, even if Shimon assisted him in opening the window. According to the Rambam, since the victim knew of the window being opened and did not object, he cannot change him mind and now object.