What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Michael is a cashier or David is a bartender. If David were a bartender, then Susan is a lawyer. For all x_14, if x_14 were a lawyer, then x_14 is climbing a mountain. If Michael were a cashier, then Susan is a lawyer.
Nothing can be inferred from these premises.