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_12, if x_12 cooks, then x_12 is taking a plane. William is not taking a plane. If William takes a plane, then Joseph is poor. If Joseph were poor, then William is cooking.
If William takes a plane, then William is cooking can be inferred via the transitivity rule.