In this task you will be given a passage and a yes/no question based on the passage. You should answer the question using the information from the passage.
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Question: passage: Not all functions have inverse functions. In order for a function f: X → Y to have an inverse, it must have the property that for every y in Y there must be one, and only one x in X so that f(x) = y. This property ensures that a function g: Y → X will exist having the necessary relationship with f.
 question: if a function is not one to one does it have an inverse?

Answer: No


Question: passage: A signature page has a line for the signature of a passport holder. A passport is not valid until it is signed by the passport holder. If a holder is unable to sign his passport, it is to be signed by a person who has legal authority to sign on the holder's behalf.
 question: is a us passport valid if not signed?

Answer: No


Question: passage: The fourth season of the American television series The Flash, which is based on the DC Comics character Barry Allen / Flash, follows a crime scene investigator with superhuman speed who fights criminals, including others who have also gained superhuman abilities. It is set in the Arrowverse, sharing continuity with the other television series of the universe, and is a spin-off of Arrow. The season is produced by Berlanti Productions, Warner Bros. Television, and DC Entertainment, with Andrew Kreisberg and Todd Helbing serving as showrunners.
 question: is there a 4th season of the flash?

Answer:
Yes