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: forall x_5: R_3(x_5) <-> S(x_5). R_3(i_2).
exists x: R_3(x) can be inferred via the existential generalization rule. forall x_5: R_3(x_5) -> S(x_5) can be inferred via the universal biconditional elimination rule. forall x_5: S(x_5) -> R_3(x_5) can be inferred via the universal biconditional elimination rule.