What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? It is raining if and only if Barbara is happy. It is windy if and only if it is raining. If it is windy, then Barbara is happy.
If it rains, then Barbara is happy. If it is windy, then it is raining. If Barbara were happy, then it is raining. If it rains, then it is windy.