Consider the following premises. For all x_8, if x_8 drives a car, then x_8 is sad. For all x_8, if x_8 were sad, then x_8 is driving a car. For all x_8, if x_8 were sad, then x_8 is driving a car. Richard is not driving a car. Can we infer the following from them? If we can, name the inference rule being used: Richard is sad.
 From the fact that for all x_8, if x_8 were sad, then x_8 is driving a car, and that for all x_8, if x_8 drives a car, then x_8 is sad we can infer that for all x_8, x_8 is sad if and only if x_8 will drive a car via universal biconditional introduction. From the fact that for all x_8, x_8 is sad if and only if x_8 will drive a car we can infer that for all x_8, if x_8 drives a car, then x_8 is sad via universal biconditional elimination. From the fact that for all x_8, if x_8 were sad, then x_8 is driving a car, and that for all x_8, if x_8 drives a car, then x_8 is sad we can infer that for all x_8, x_8 is sad if and only if x_8 will drive a car via universal biconditional introduction. From the fact that for all x_8, x_8 is sad if and only if x_8 will drive a car we can infer that Richard is sad if and only if Richard is driving a car via universal instantiation. Finally, from the fact that Richard is sad if and only if Richard is driving a car, and that Richard is not driving a car we can infer that Richard is not sad via biconditional elimination, which contradicts that Richard is sad. Therefore, the answer is no.