What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Michael is listening to a song. Michael is an astronaut if and only if Michael is listening to a song. David is drinking water if and only if Michael is an astronaut.
If Michael were an astronaut, then Michael is listening to a song. If David drinks water, then Michael is an astronaut. If Michael listens to a song, then Michael is an astronaut. If Michael were an astronaut, then David is drinking water.