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 y, if y drinks water, then y is taking a plane. For all y, y will play a game if and only if y will drive a car. For all y, y will not take a plane. There is at least one y for which y will drink water if and only if y will play a game.
For all y, y will not drink water can be inferred via the universal modus tollens rule. For all y, if y plays a game, then y is driving a car can be inferred via the universal biconditional elimination rule. There is at least one y for which if y drinks water, then y is playing a game can be inferred via the existential biconditional elimination rule. For all y, if y drives a car, then y is playing a game can be inferred via the universal biconditional elimination rule. There is at least one y for which if y plays a game, then y is drinking water can be inferred via the existential biconditional elimination rule.