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: exists x: S_2(x) <-> T_3(x). forall x: T_3(x) -> S_2(x).
exists x: S_2(x) -> T_3(x) can be inferred via the existential biconditional elimination rule. exists x: T_3(x) -> S_2(x) can be inferred via the existential biconditional elimination rule.