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: Karen is not listening to a song. John is playing tennis if and only if Karen is listening to a song. Robert is an artist or John is playing tennis. Robert is not an artist or Joseph is a writer.
John is playing tennis or Joseph is a writer can be inferred via the resolution rule. If John plays tennis, then Karen is listening to a song can be inferred via the biconditional elimination rule. If Karen listens to a song, then John is playing tennis can be inferred via the biconditional elimination rule. John is not playing tennis can be inferred via the biconditional elimination rule.