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_8 <-> P_15(a_14). forall x_15: ~Q_15(x_15). forall x_15: P_15(x_15) -> Q_15(x_15).
p_8 -> P_15(a_14) can be inferred via the biconditional elimination rule. P_15(a_14) -> p_8 can be inferred via the biconditional elimination rule. forall x_15: ~P_15(x_15) can be inferred via the universal modus tollens rule.