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_17, x_17 will take a plane if and only if x_17 will cook. For all x_17, x_17 is excited or x_17 is a police officer. For all x_17, x_17 is not excited. There is at least one x_17 for which if x_17 were a police officer, then x_17 is cooking.
For all x_17, x_17 is a police officer can be inferred via the universal disjunctive syllogism rule. For all x_17, if x_17 takes a plane, then x_17 is cooking can be inferred via the universal biconditional elimination rule. For all x_17, if x_17 cooks, then x_17 is taking a plane can be inferred via the universal biconditional elimination rule.