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(b) <-> q. forall x_15: Q_15(x_15) <-> P(x_15). forall x_15: P_15(x_15) or ~Q_15(x_15). forall x_15: ~P_15(x_15).
P(b) -> q can be inferred via the biconditional elimination rule. q -> P(b) can be inferred via the biconditional elimination rule. forall x_15: Q_15(x_15) -> P_15(x_15) can be inferred via the universal rewriting rule. forall x_15: Q_15(x_15) -> P(x_15) can be inferred via the universal biconditional elimination rule. forall x_15: P(x_15) -> Q_15(x_15) can be inferred via the universal biconditional elimination rule.