Subgame Perfect Equilibrium
Table:
Subgame Perfect Equilibrium
Subset of	Nash equilibrium
Intersects with	Evolutionarily stable strategy
Proposed by	Reinhard Selten
Used for	Extensive form games
Example	Ultimatum game

Based on the table, identify if the claim is entailed, neutral, or refuted. Give your final answer in JSON format {"answer": "YOUR ANSWER"}.

Statement: Used for extensive form games, the Ultimatum game is an example of Subgame Perfect Equilibrium.

answer: entailed