Consider the following premises. If Robert goes running, then it is sunny. For all x_12, x_12 will go running and x_12 is a sailor. Can we infer the following from them? If we can, name the inference rule being used: It is sunny.
 From the fact that for all x_12, x_12 will go running and x_12 is a sailor we can infer that for all x_12, x_12 will go running via universal simplification. From the fact that for all x_12, x_12 will go running we can infer that Robert is running via universal instantiation. Finally, from the fact that if Robert goes running, then it is sunny, and that Robert is running we can infer that it is sunny via modus ponens. Therefore, the answer is yes.