What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Name the inference rule being used: It is not late. Richard is a server if and only if Jennifer is reading a book. It is late or it is cloudy. Jennifer is reading a book.
It is cloudy can be inferred via the disjunctive syllogism rule. It is not late and Jennifer is reading a book can be inferred via the conjunction rule. Jennifer is reading a book and it is not late can be inferred via the conjunction rule. If Richard were a server, then Jennifer is reading a book can be inferred via the biconditional elimination rule. If Jennifer reads a book, then Richard is a server can be inferred via the biconditional elimination rule.