What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Elisabeth is an artist if and only if William is a police officer. Jessica is a writer. Elisabeth is not an artist.
Jessica is a writer and Elisabeth is not an artist. Elisabeth is not an artist and Jessica is a writer. If Elisabeth were an artist, then William is a police officer. If William were a police officer, then Elisabeth is an artist. William is not a police officer.