What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? If Jennifer were excited, then Susan is not a police officer. If Robert writes a letter, then Robert is taking a plane. Susan is a police officer. If Robert takes a plane, then Jennifer is excited.
Jennifer is not excited. If Robert writes a letter, then Jennifer is excited. If Robert takes a plane, then Susan is not a police officer.