What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? It is not sunny. If it is late, then it is sunny. If it is sunny, then it is late. Barbara is not a carpenter or it is cloudy. Barbara is a carpenter or it is late.
It is not late. It is late or it is cloudy. It is late if and only if it is sunny. It is sunny if and only if it is late.