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1. Broken pieces of a mat may be moved on Shabbos.
2. If a gourd is used as a pail for a well and it is functional, it is not Muktzah.
3. There is dispute about whether one may use a window stopper (a board or curtain used to cover the opening), and under what conditions.
4. If one mistakenly leaves a stone (Muktzah) on top of his wine barrel, he may tip the barrel to cause it to fall off.
5. There is a dispute about whether one may add onto a temporary Ohel on Shabbos and Yom Tov.
A BIT MORE
1. This is because they still serve a useful purpose. (It happens to be that they still serve even their original purpose, although this is not required. -Tosfos)
2. Even if there is a stone in it the pail to help weigh it down to get the water, the stone is considered part of the pail (i.e. the gourd). However, if the gourd does not work well in this capacity, the entire gourd may be Muktzah, as the stone causes the gourd to be a Basis l'Davar ha'Asur.
3. Rebbi Eliezer: One may use it only if it is tied to the wall and it does not drag on the ground, for otherwise it appears as though he is adding to the building (Boneh). Chachamim: One may use it even without these conditions being fulfilled.
4. This leniency applies only if he forgot the stone there. If he intended for it to be there from before Shabbos, there is a dispute about whether the entire barrel is Muktzah because it becomes a Basis, or whether the stone becomes the cover of the barrel and one may move the stone in a normal manner.
5. While everyone agrees one may not make even a temporary Ohel on Shabbos and Yom Tov, Rebbi Eliezer maintains that one may not even add on to a temporary Ohel, while the Chachamim say that this is permitted.
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