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: W_3(y) -> R(y). forall y: R(y) -> W_3(y). forall y: W_3(y) or R_4(y). forall y: R_4(y) <-> R(y).
forall y: W_3(y) <-> R(y) can be inferred via the universal biconditional introduction rule. forall y: R(y) <-> W_3(y) can be inferred via the universal biconditional introduction rule. forall y: R_4(y) -> R(y) can be inferred via the universal biconditional elimination rule. forall y: R(y) -> R_4(y) can be inferred via the universal biconditional elimination rule.