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 it is late, then Robert is listening to a song. It is snowing. If John were a scientist, then it is late. If Robert listens to a song, then it is not snowing.
Robert is not listening to a song can be inferred via the modus tollens rule. If it is late, then it is not snowing can be inferred via the transitivity rule. If John were a scientist, then Robert is listening to a song can be inferred via the transitivity rule.