(Temporary Ohel) What are some of the conditions and guidelines to go along with temporary roofing, shelter, etc.
floor Drain with Hinges or Handle, Shelf in a Bookcase with Hinges, and the Use of a High Riser or Sofa Bed on Shabbos;
How long does a knot have to be tied to be considered a "קשר של קימא". (Knot of permanence).