What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? If it is sunny, then Michael is an astronaut. It is sunny if and only if Michael is an astronaut. If Michael were an astronaut, then it is sunny.
It is sunny if and only if Michael is an astronaut. Michael is an astronaut if and only if it is sunny. If it is sunny, then Michael is an astronaut. If Michael were an astronaut, then it is sunny.