Consider the following premises. There is at least one x_13 for which x_13 is not a lawyer. For all x_13, if x_13 were a lawyer, then x_13 is driving a car. For all x_13, x_13 is a lawyer if and only if x_13 will drive a car. For all x_13, if x_13 climbs a mountain, then x_13 is driving a car. Can we infer the following from them? There is at least one x_13 for which x_13 will not climb a mountain.
 From the fact that for all x_13, x_13 is a lawyer if and only if x_13 will drive a car we can infer that for all x_13, if x_13 drives a car, then x_13 is a lawyer. From the fact that for all x_13, if x_13 were a lawyer, then x_13 is driving a car, and that for all x_13, if x_13 drives a car, then x_13 is a lawyer we can infer that for all x_13, x_13 is a lawyer if and only if x_13 will drive a car. From the fact that for all x_13, x_13 is a lawyer if and only if x_13 will drive a car, and that there is at least one x_13 for which x_13 is not a lawyer we can infer that there is at least one x_13 for which x_13 will not drive a car. Finally, from the fact that for all x_13, if x_13 climbs a mountain, then x_13 is driving a car, and that there is at least one x_13 for which x_13 will not drive a car we can infer that there is at least one x_13 for which x_13 will not climb a mountain. Therefore, the answer is yes.