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