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