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: Q_4(x) -> P(x). forall x: P(x) <-> R(x). forall x: R(x) -> Q_4(x).
exists x: R(x) -> P(x) can be inferred via the existential transitivity rule. forall x: P(x) -> R(x) can be inferred via the universal biconditional elimination rule. forall x: R(x) -> P(x) can be inferred via the universal biconditional elimination rule.