What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? If Mary were a nurse, then Patricia is a writer. Patricia is a writer if and only if it is cold. If Patricia were a writer, then Mary is a nurse. Mary is not a nurse. If it is cold, then Patricia is a writer.
Patricia is not a writer. If it is cold, then Mary is a nurse. Mary is a nurse if and only if Patricia is a writer. Patricia is a writer if and only if Mary is a nurse. If Patricia were a writer, then it is cold. If it is cold, then Patricia is a writer.