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: For all x_17, x_17 will not sleep. Susan is a sailor if and only if it is raining. If Mary were rich, then Susan is a sailor. If it rains, then Robert is sleeping. If Robert sleeps, then it is raining.
If Susan were a sailor, then it is raining can be inferred via the biconditional elimination rule. If it rains, then Susan is a sailor can be inferred via the biconditional elimination rule.