Consider the following premises. Jessica is a politician and Karen is a sailor. If Jessica were a politician, then David is a scientist. Can we infer the following from them? If we can, name the inference rule being used: David is a scientist.
 From the fact that Jessica is a politician and Karen is a sailor we can infer that Jessica is a politician via simplification. Finally, from the fact that if Jessica were a politician, then David is a scientist, and that Jessica is a politician we can infer that David is a scientist via modus ponens. Therefore, the answer is yes.