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 y_2: P(y_2) <-> P_1(y_2). forall y_2: ~P(y_2). P_1(a_5) or w.
forall y_2: P(y_2) -> P_1(y_2) can be inferred via the universal biconditional elimination rule. forall y_2: P_1(y_2) -> P(y_2) can be inferred via the universal biconditional elimination rule. forall y_2: ~P_1(y_2) can be inferred via the universal biconditional elimination rule.