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_12: Q_12(x_12) -> P_12(x_12). exists x_12: ~P_7(x_12) or P_12(x_12). forall x_12: P_7(x_12) or U(x_12). forall x_12: Q_12(x_12) or ~U(x_12). forall x_12: P_12(x_12) -> Q_12(x_12).
exists x_12: U(x_12) or P_12(x_12) can be inferred via the existential resolution rule. forall x_12: U(x_12) -> Q_12(x_12) can be inferred via the universal rewriting rule. forall x_12: Q_12(x_12) <-> P_12(x_12) can be inferred via the universal biconditional introduction rule. forall x_12: P_12(x_12) <-> Q_12(x_12) can be inferred via the universal biconditional introduction rule.