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: If Elisabeth listens to a song, then Barbara is an artist. Jessica is drinking water if and only if Elisabeth is listening to a song. If Barbara were an artist, then Elisabeth is listening to a song.
Elisabeth is listening to a song if and only if Barbara is an artist can be inferred via the biconditional introduction rule. Barbara is an artist if and only if Elisabeth is listening to a song can be inferred via the biconditional introduction rule. If Jessica drinks water, then Elisabeth is listening to a song can be inferred via the biconditional elimination rule. If Elisabeth listens to a song, then Jessica is drinking water can be inferred via the biconditional elimination rule.