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_5, if x_5 drives a car, then x_5 is a scientist. For all x_5, if x_5 were a scientist, then x_5 is driving a car. There is at least one x_5 for which x_5 is a server if and only if x_5 is a scientist. For all x_5, x_5 will not drive a car.
For all x_5, x_5 is not a scientist can be inferred via the universal modus tollens rule. For all x_5, x_5 will drive a car if and only if x_5 is a scientist can be inferred via the universal biconditional introduction rule. For all x_5, x_5 is a scientist if and only if x_5 will drive a car can be inferred via the universal biconditional introduction rule. There is at least one x_5 for which if x_5 were a server, then x_5 is a scientist can be inferred via the existential biconditional elimination rule. There is at least one x_5 for which if x_5 were a scientist, then x_5 is a server can be inferred via the existential biconditional elimination rule.