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_2, if x_2 were a doctor, then x_2 is drinking water. For all x_2, if x_2 drinks water, then x_2 is a doctor. For all x_2, if x_2 were a lawyer, then x_2 is drinking water. For all x_2, x_2 is not a lawyer. For all x_2, if x_2 drinks water, then x_2 is a lawyer.
For all x_2, x_2 will not drink water can be inferred via the universal modus tollens rule. For all x_2, if x_2 were a doctor, then x_2 is a lawyer can be inferred via the universal transitivity rule. For all x_2, if x_2 were a lawyer, then x_2 is a doctor can be inferred via the universal transitivity rule. For all x_2, x_2 is a doctor if and only if x_2 will drink water can be inferred via the universal biconditional introduction rule. For all x_2, x_2 will drink water if and only if x_2 is a doctor can be inferred via the universal biconditional introduction rule. For all x_2, x_2 is a lawyer if and only if x_2 will drink water can be inferred via the universal biconditional introduction rule. For all x_2, x_2 will drink water if and only if x_2 is a lawyer can be inferred via the universal biconditional introduction rule.