Consider the following premises. David is climbing a mountain if and only if Richard is drinking water. If John takes a plane, then Richard is drinking water. For all x_13, x_13 will take a plane or x_13 will read a book. David is not climbing a mountain. Can we infer the following from them? If we can, name the inference rule being used: John is not reading a book.
 From the fact that for all x_13, x_13 will take a plane or x_13 will read a book we can infer that John is taking a plane or John is reading a book via universal instantiation. From the fact that David is climbing a mountain if and only if Richard is drinking water, and that David is not climbing a mountain we can infer that Richard is not drinking water via biconditional elimination. From the fact that if John takes a plane, then Richard is drinking water, and that Richard is not drinking water we can infer that John is not taking a plane via modus tollens. Finally, from the fact that John is taking a plane or John is reading a book, and that John is not taking a plane we can infer that John is reading a book via disjunctive syllogism, which contradicts that John is not reading a book. Therefore, the answer is no.