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 not play tennis or y will play a game. For all y, y will play tennis or y will play squash. For all y, if y plays squash, then y is listening to a song. For all y, y will play a game if and only if y will listen to a song.
There is at least one y for which y will play squash or y will play a game can be inferred via the existential resolution rule. For all y, if y plays a game, then y is listening to a song can be inferred via the universal biconditional elimination rule. For all y, if y listens to a song, then y is playing a game can be inferred via the universal biconditional elimination rule.