Consider the following premises. For all x_6, if x_6 drives a car, then x_6 is taking a plane. For all x_6, if x_6 were a server, then x_6 is driving a car. If it is sunny, then Robert is taking a plane. It is sunny or Robert is a server. Can we infer the following from them? If we can, name the inference rule being used: Robert is not taking a plane.
 From the fact that for all x_6, if x_6 were a server, then x_6 is driving a car, and that for all x_6, if x_6 drives a car, then x_6 is taking a plane we can infer that for all x_6, if x_6 were a server, then x_6 is taking a plane via universal transitivity. From the fact that for all x_6, if x_6 were a server, then x_6 is taking a plane we can infer that if Robert were a server, then Robert is taking a plane via universal instantiation. Finally, from the fact that if it is sunny, then Robert is taking a plane, that if Robert were a server, then Robert is taking a plane, and that it is sunny or Robert is a server we can infer that Robert is taking a plane via disjunction elimination, which contradicts that Robert is not taking a plane. Therefore, the answer is no.