Question: Which case is cited as the business purpose doctrine: Gregory v. Helvering or Ableman v. Booth?
Sentence (from "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.
Relevant evidence: Yes