2. Even if there is three tefachim open space between the upper reed and the lower reed, the Sukkah will only be invalid if the top of the reeds is not a tefach wide. If the top level of the reeds is a tefach wide, however, then the Sukkah will be valid. The reason for this ruling is because we say chavot remi, lower and place the top reeds on the space below. (22a2)
3. The Mishnah in Oholos states that if the beams of a two-story house do not have plaster on them, and the beams are placed corresponding to each other, if there is corpse tumah beneath one of the lower beams, any vessel that is underneath that beam will be tamei. If the tumah is between the lower and upper beam, however, a vessel that is between the beams will be tamei. If the tumah is above the upper beam, a vessel that is opposite the tumah above the beam until the heaven is tamei. (22a2)
4. Regarding a mavoi that requires an adjustment of a korah or a lechi, if a korah extends from one wall of a mavoi and does not extend to the other wall of the mavoi, or two korahs extend from two opposite walls and the korahs are not long enough to reach each other, there is a dispute. The Tanna Kamma maintains that if the space between the beams is less than three tefachim wide, we apply the principle of lavud and the space is deemed to be closed and one can carry within the entranceway. If the space between the beams is more than three tefachim, however, one must fill in the space with another korah. Rabban Shimon ben Gamliel maintains that if the space between the two korahs or between the korah and the wall is less than four tefachim wide, one is not required to bring another korah. If the space is more than four tefachim, however, one must bring another korah to close off the space. Rabban Shimon ben Gamliel maintains that we apply the principle of lavud to a space that is les than four tefachim. (22a3-22b1)
5. We learned previously on Daf 2a that a Sukkah that has more sunlight than shade is invalid, implying that if the sunlight and shade were equal, then the Sukkah would be valid. Yet, the Mishna here states that if the shade is more than the sunlight, the Sukkah is valid, which implies that if the shade and sunlight are equal, then the Sukkah is invalid. The Gemara answers that our Mishna refers to the shade and sunlight above, i.e. the thickness of the s’chach itself, which means that there is more solid s’chach than open space. This implies that if the solid part of the s’chach is equal to the open space, the Sukkah is invalid because there will be more sunlight than shade on the floor of the Sukkah. The Mishna on Daf 2a, however, refers to the shade and sunlight on the floor of the Sukkah. When there is more sunlight than shade, the Sukkah is invalid. Yet, if the shade and sunlight on the Sukkah floor are equal, the Sukkah is deemed to be valid because equal sunlight and shade on the Sukkah floor indicates that there is more solid s’chach above than opens space. (22b2)