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: There is at least one y for which y will take a plane or y will not play a game. For all y, if y takes a plane, then y is happy. For all y, y will play a game or y is not happy.
For all y, if y were happy, then y is playing a game can be inferred via the universal rewriting rule. There is at least one y for which if y plays a game, then y is taking a plane can be inferred via the existential rewriting rule.