What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? It is snowing if and only if William is an electrician. John is playing tennis if and only if it is sunny. John is not playing tennis. For all x_23, x_23 is not an electrician.
If it snows, then William is an electrician. If John plays tennis, then it is sunny. If William were an electrician, then it is snowing. If it is sunny, then John is playing tennis. It is not sunny.