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, if z were a cashier, then z is not working. For all z, z will drink water if and only if z is curious. For all z, z will work. There is at least one z for which z is a cashier if and only if z will drink water.
For all z, z is not a cashier can be inferred via the universal modus tollens rule. For all z, if z drinks water, then z is curious can be inferred via the universal biconditional elimination rule. There is at least one z for which if z were a cashier, then z is drinking water can be inferred via the existential biconditional elimination rule. For all z, if z were curious, then z is drinking water can be inferred via the universal biconditional elimination rule. There is at least one z for which if z drinks water, then z is a cashier can be inferred via the existential biconditional elimination rule.