1. The Gemara concludes that everyone agrees that one is permitted to carry directly below the Korah.
2. There is a dispute about whether a Korah functions as a reminder or as a wall.
3. There is a dispute about the minimum area of a Mavoy.
4. Beraisa: Carrying in a Mavoy may be permitted with a Korah or Lechi (vertical pole) only if there are houses and courtyards opening into the Mavoy.
5. If part of the wall of the Mavoy was built in such a way that it protrudes into the entranceway (such as an "L" shaped wall), it may be considered a Lechi to permit carrying in the Mavoy.
A BIT MORE
1. The outer side of the Korah (facing the Reshus ha'Rabim) is considered where the area of the Mavoy ends.
2. According to one opinion, the side of the Korah is considered to descend and create a wall, rendering the Mavoy enclosed by four walls (and thereby making it a Reshus ha'Yachid). The other, more accepted opinion is that it serves merely to remind people not to carry past that point (beyond the Mavoy into the Reshus ha'Rabim).
3. Rav Yosef: The area must be four Tefachim in order to have the status of a Mavoy. Abaye: The area must be four Amos.
4. Rav Nachman adds that the length of the Mavoy must be greater than its width.
5. This is true only when it protrudes into the entranceway by a length of less than four Amos.