A gentile seizes a Jew's field for a debt and sells it to another Jew. When is the sale valid?
Halachot 1–2: The sale is valid when the original owner admits the seizure's justification or two Jewish witnesses substantiate the gentile's claim.
Question 2
An unauthorized squatter plants trees in a colleague's field. What can the field owner demand?
Halacha 4: The owner of the field may tell the squatter to uproot his tree and go — the owner's wishes are heeded.
Question 3
What did the Geonim rule regarding a squatter who builds in another's courtyard without permission?
Halacha 5: The Geonim ruled that a squatter who builds in a courtyard without permission may only be removed when the owner pays for the improvements.
Question 4
When a squatter enters a field with the owner's permission and improves it, how much does the owner owe?
Halacha 6: When a person enters with the owner's permission, his improvement is evaluated and he receives the lesser of his expenses or the increase in value.
Question 5
When improvements are evaluated 'at the improver's disadvantage,' from what property may he collect?
Halacha 9: When evaluated at disadvantage, the improver is not entitled to collect from encumbered property — only from free property.