What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_9, if x_9 were a politician, then x_9 is listening to a song. For all x_9, if x_9 listens to a song, then x_9 is a politician. There is at least one x_9 for which x_9 will not listen to a song. For all x_9, x_9 is a politician if and only if x_9 is a writer.
There is at least one x_9 for which x_9 is not a politician. For all x_9, x_9 is a politician if and only if x_9 will listen to a song. For all x_9, x_9 will listen to a song if and only if x_9 is a politician. For all x_9, if x_9 were a politician, then x_9 is a writer. For all x_9, if x_9 were a writer, then x_9 is a politician.