What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? It is sunny. Linda is a police officer if and only if James is a nurse. If it is sunny, then it is snowing. If it snows, then James is a nurse.
It is snowing. If it is sunny, then James is a nurse. If Linda were a police officer, then James is a nurse. If James were a nurse, then Linda is a police officer.