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 z, z is a nurse if and only if z is bored. For all z, if z drinks water, then z is a nurse. For all z, if z were a nurse, then z is drinking water. For all z, z will not drink water.
For all z, z is not a nurse can be inferred via the universal modus tollens rule. For all z, z will drink water if and only if z is a nurse can be inferred via the universal biconditional introduction rule. For all z, z is a nurse if and only if z will drink water can be inferred via the universal biconditional introduction rule. For all z, if z were a nurse, then z is bored can be inferred via the universal biconditional elimination rule. For all z, if z were bored, then z is a nurse can be inferred via the universal biconditional elimination rule.