What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? exists y_2: R_2(y_2) <-> P(y_2). forall y_2: P(y_2) <-> R(y_2). forall y_2: R_2(y_2) -> R(y_2).
forall y_2: P(y_2) -> R(y_2). exists y_2: R_2(y_2) -> P(y_2). forall y_2: R(y_2) -> P(y_2). exists y_2: P(y_2) -> R_2(y_2).