A closed lane (3 walls, one open end) — what does it need to permit carrying?
A closed lane needs just a pole (lechi) at the open side, or a beam (korah) spanning the top. Either creates the halachic boundary needed.
Question 2
What is a lechi?
A lechi is a vertical post at the side of an opening. It can be any material — wood, stone, even a living person or animal — as long as it's positioned correctly.
Question 3
The well-enclosure leniency (8 corner walls) applies where?
This leniency was specifically for festival pilgrims in Eretz Yisrael who needed to water their animals. It doesn't apply to private use or outside Israel.
Question 4
A lane wider than 10 cubits — can a simple pole or beam permit it?
Once a lane exceeds 10 cubits in width, a simple pole or beam isn't sufficient. A full doorframe structure (two posts + crossbeam) is required.
Question 5
Can a living person or animal serve as a lechi (pole) for an eruv?
The Rambam explicitly permits it: a lechi can be constructed from any substance, including a living entity. The function (marking the boundary) matters more than the material.