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, x_12 is a politician or x_12 is a lawyer. For all x_12, if x_12 were a politician, then x_12 is taking a plane. For all x_12, if x_12 were a lawyer, then x_12 is taking a plane. For all x_12, x_12 is a bartender if and only if x_12 is rich. For all x_12, if x_12 were a mechanic, then x_12 is a bartender. For all x_12, x_12 is rich or x_12 is a mechanic.
For all x_12, x_12 will take a plane can be inferred via the universal disjunction elimination rule. For all x_12, if x_12 were a bartender, then x_12 is rich can be inferred via the universal biconditional elimination rule. For all x_12, if x_12 were rich, then x_12 is a bartender can be inferred via the universal biconditional elimination rule.