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: There is at least one x_3 for which x_3 is curious if and only if x_3 is a politician. For all x_3, x_3 is a politician or x_3 is not curious.
For all x_3, if x_3 were curious, then x_3 is a politician can be inferred via the universal rewriting rule. There is at least one x_3 for which if x_3 were curious, then x_3 is a politician can be inferred via the existential biconditional elimination rule. There is at least one x_3 for which if x_3 were a politician, then x_3 is curious can be inferred via the existential biconditional elimination rule.