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_13: Q_13(x_13) -> P_13(x_13). Q_13(f) or ~t. forall x_13: P_13(x_13) -> Q_13(x_13).
t -> Q_13(f) can be inferred via the rewriting rule. forall x_13: Q_13(x_13) <-> P_13(x_13) can be inferred via the universal biconditional introduction rule. forall x_13: P_13(x_13) <-> Q_13(x_13) can be inferred via the universal biconditional introduction rule.