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_1. forall x_14: Q_14(x_14) -> P_14(x_14). forall x_14: P_14(x_14) -> Q_14(x_14). ~P_14(a_13).
p_1 and ~P_14(a_13) can be inferred via the conjunction rule. ~P_14(a_13) and p_1 can be inferred via the conjunction rule. forall x_14: Q_14(x_14) <-> P_14(x_14) can be inferred via the universal biconditional introduction rule. forall x_14: P_14(x_14) <-> Q_14(x_14) can be inferred via the universal biconditional introduction rule.