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_10, if x_10 were a politician, then x_10 is bored. For all x_10, if x_10 were bored, then x_10 is a politician. If John were bored, then Joseph is listening to a song.
For all x_10, x_10 is a politician if and only if x_10 is bored can be inferred via the universal biconditional introduction rule. For all x_10, x_10 is bored if and only if x_10 is a politician can be inferred via the universal biconditional introduction rule.