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_2(d) or q. forall y_1: P(y_1) -> P_2(y_1). q -> P(d). forall y_1: P_2(y_1) -> P(y_1).
forall y_1: P(y_1) <-> P_2(y_1) can be inferred via the universal biconditional introduction rule. forall y_1: P_2(y_1) <-> P(y_1) can be inferred via the universal biconditional introduction rule.