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: R(y) -> R_1(y). forall y: R_1(y) -> R(y). R_1(a) -> R(a).
forall y: R(y) <-> R_1(y) can be inferred via the universal biconditional introduction rule. forall y: R_1(y) <-> R(y) can be inferred via the universal biconditional introduction rule.