context: a boy wearing jean shorts, and a black and blue shirt, reading a book, sits on a rolling device up against a wall that says book fair, while other people stand around.
hypothesis: It is probably the case that a boy reads a mystery book.
valid_hypothesis: We doubt that a boy reads a mystery book.
invalid_hypothesis: It is probably the case that a boy reads a mystery book.
hypothesis_assertion: A boy reads a mystery book.