What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? If it rains, then Joseph is sad. Joseph is not sad. Jessica is playing squash. If Joseph were sad, then it is raining.
It is not raining. Joseph is not sad and Jessica is playing squash. Jessica is playing squash and Joseph is not sad. It is raining if and only if Joseph is sad. Joseph is sad if and only if it is raining.