premise: The Aristocrats is a 2005 American documentary comedy film about the famous dirty joke of the same name. It was conceived and produced by comedians Penn Jillette and Paul Provenza, edited by Emery Emery, and released theatrically by TH!NKFilm. The film is dedicated to Johnny Carson, as "The Aristocrats" was said to be his favorite joke.
hypothesis: The Aristocrats is about a dirty joke that existed before the film was created.
reason: The film is about a famous dirty joke. If the joke didn't already exist prior to the creation of the film, there would be no reason to create the film. Therefore the statement is definitely correct. I think the system found this to be difficult because it requires logical thinking and justification. 