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: P_17(a_5). forall x: Q(x) -> P_17(x). forall x: P_17(x) <-> Q(x).
exists x: P_17(x) can be inferred via the existential generalization rule. forall x: P_17(x) -> Q(x) can be inferred via the universal biconditional elimination rule. forall x: Q(x) -> P_17(x) can be inferred via the universal biconditional elimination rule.