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, y will take a plane if and only if y will play a game. There is at least one y for which y will not play a game. For all y, y will take a plane or y is excited.
For all y, if y takes a plane, then y is playing a game can be inferred via the universal biconditional elimination rule. For all y, if y plays a game, then y is taking a plane can be inferred via the universal biconditional elimination rule. There is at least one y for which y will not take a plane can be inferred via the existential biconditional elimination rule.