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_4, y_4 will not listen to a song. Thomas is climbing a mountain if and only if Linda is listening to a song.
If Thomas climbs a mountain, then Linda is listening to a song can be inferred via the biconditional elimination rule. If Linda listens to a song, then Thomas is climbing a mountain can be inferred via the biconditional elimination rule.