Which case is cited as the business purpose doctrine: Gregory v. Helvering or Ableman v. Booth?
Ableman v. Booth Ableman v. Booth, 62 U.S. 506 (1859) , was a United States Supreme Court case in which the Court held that State courts cannot issue rulings on federal law that contradict the decisions of federal courts, overturning a decision by the Supreme Court of Wisconsin. The Supreme Court held that under the Constitution, the federal courts have the final power to decide cases arising under the Constitution and federal statutes, and that the States do not have the power to overturn those decisions. Thus, Wisconsin did not have the authority to nullify federal judgments or statutes.
Shelter rule The shelter rule is a doctrine in the common law of property under which a grantee who has received an interest in property from a bona fide purchaser will also be protected as a bona fide purchaser, even if the grantee would not legally qualify for this status. The grantee is "sheltered" from other claims by the grantor's status as an actual bona fide purchaser.