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_13, x_13 is curious if and only if x_13 is a politician. For all x_13, x_13 is a politician if and only if x_13 is curious. There is at least one x_13 for which if x_13 were a politician, then x_13 is cooking.
For all x_13, if x_13 were curious, then x_13 is a politician can be inferred via the universal biconditional elimination rule. For all x_13, if x_13 were a politician, then x_13 is curious can be inferred via the universal biconditional elimination rule. For all x_13, if x_13 were a politician, then x_13 is curious can be inferred via the universal biconditional elimination rule. For all x_13, if x_13 were curious, then x_13 is a politician can be inferred via the universal biconditional elimination rule.