What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Name the inference rule being used: For all x_6, if x_6 writes a letter, then x_6 is driving a car. Karen is not driving a car. For all x_6, if x_6 were poor, then x_6 is writing a letter.
For all x_6, if x_6 were poor, then x_6 is driving a car can be inferred via the universal transitivity rule.