Rif Succah 1b {Succah 2b continues; 3b - 4a}

HIDE/SHOW IMAGE
1b

{Succah 2b continues}
and Rabbi Yehuda, who declares it valid, maintains that a succah must be a permanent dwelling, and the halacha is not like him {Rabbi Yehuda}. And if the walls reach the schach, it is all the more a permanent dwelling; and furthermore, the sugya about a succah atop another succah is predicated and related to Rava's opinion.

{Succah 3b}
If it was higher than 20 cubits and he came to reduce it with matresses and cushions, it is not a reduction.
{Succah 4a}
and even though he nullified it, his opinion is nullified against those of everyone else.
Straw and he nullified it, it is a reduction, and certainly dirt and he nullified it.

If it was higher than 20 cubits and foliage descends within 20, if the shade {specifically of the foliage which descended under 20} is more than the sun, it is valid, and if not, it is invalid.

If it was 10 handbreadths high and foliage descends to within 10 handbreadths, Abaye maintains that if its sun is more than its shade, it is valid.
Rava said to him: This is an offensive {annoying} dwelling, and one does not dwell in an offensive dwelling. {and teshvu ke'en taduru}

If it was higher than 20 cubits and he built inside it a platform along the entire middle wall, if there is in it {the area of the platform, in which there in now 20 cubits or less to the sechach} the required space for a valid succah, it is valid, and if not it is invalid.

If {he constructed the platform} along a side {wall}, if there is from the edge of the platform until the {opposite} wall 4 cubits it is invalid, and if not it is valid.

If it was higher than 20 cubits and he built the platform in the center, if there is from the edge of the platform until the wall in each {of the two} direction 4 cubits it is invalid, and if not it is valid, for we say that there is a crooked wall {that is, the sechach for up but not including 4 cubits is considered part of the wall, and so it is up against the wall} in both directions.

If it was less than 10 handbreadths and he dug out in it {a trench} in order to complete it to 10 handbreadths, if there is from the edge of the trench until the wall 3 handbreadths it is invalid; less than 3 handbreadths it is valid {lavud}.