What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Jennifer is a server if and only if Barbara is an office clerk. Jennifer is not a server. For all x, x is an office clerk if and only if x is a lawyer.
If Jennifer were a server, then Barbara is an office clerk. If Barbara were an office clerk, then Jennifer is a server. Barbara is not an office clerk. For all x, if x were an office clerk, then x is a lawyer. For all x, if x were a lawyer, then x is an office clerk.