Consider the following premises. For all x_6, if x_6 were a sailor, then x_6 is rich. For all x_6, if x_6 were a sailor, then x_6 is climbing a mountain. There is at least one x_6 for which if x_6 drinks water, then x_6 is rich. For all x_6, x_6 will not climb a mountain. For all x_6, if x_6 were rich, then x_6 is a sailor. Can we infer the following from them? If we can, name the inference rule being used: For all x_6, x_6 will drink water.
 From the fact that for all x_6, if x_6 were a sailor, then x_6 is climbing a mountain, and that for all x_6, x_6 will not climb a mountain we can infer that for all x_6, x_6 is not a sailor via universal modus tollens. From the fact that for all x_6, if x_6 were a sailor, then x_6 is rich, and that for all x_6, if x_6 were rich, then x_6 is a sailor we can infer that for all x_6, x_6 is a sailor if and only if x_6 is rich via universal biconditional introduction. From the fact that for all x_6, x_6 is a sailor if and only if x_6 is rich, and that for all x_6, x_6 is not a sailor we can infer that for all x_6, x_6 is not rich via universal biconditional elimination. Finally, from the fact that there is at least one x_6 for which if x_6 drinks water, then x_6 is rich, and that for all x_6, x_6 is not rich we can infer that there is at least one x_6 for which x_6 will not drink water via existential modus tollens, which contradicts that For all x_6, x_6 will drink water. Therefore, the answer is no.