What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Name the inference rule being used: If Michael goes running, then it is raining. If Robert plays tennis, then it is not raining. It is raining if and only if Jennifer is a doctor. Jennifer is a doctor or Michael is running.
If it rains, then Jennifer is a doctor can be inferred via the biconditional elimination rule. If Jennifer were a doctor, then it is raining can be inferred via the biconditional elimination rule.