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: There is at least one x for which x is an office clerk if and only if x is a lawyer. For all x, x is a lawyer or x is not an office clerk.
For all x, if x were an office clerk, then x is a lawyer can be inferred via the universal rewriting rule. There is at least one x for which if x were an office clerk, then x is a lawyer can be inferred via the existential biconditional elimination rule. There is at least one x for which if x were a lawyer, then x is an office clerk can be inferred via the existential biconditional elimination rule.