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 Susan were an astronaut, then David is reading a book. If David drives a car, then it is snowing. For all x_15, if x_15 reads a book, then x_15 is driving a car. If it is late, then Susan is an astronaut. If Charles listens to a song, then it is late.
If it is late, then David is reading a book can be inferred via the transitivity rule. If Charles listens to a song, then Susan is an astronaut can be inferred via the transitivity rule.