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: S_7(i_3) <-> R(i). forall y_4: ~R(y_4). forall x_7: U(x_7) <-> S_7(x_7).
S_7(i_3) -> R(i) can be inferred via the biconditional elimination rule. R(i) -> S_7(i_3) can be inferred via the biconditional elimination rule. forall x_7: U(x_7) -> S_7(x_7) can be inferred via the universal biconditional elimination rule. forall x_7: S_7(x_7) -> U(x_7) can be inferred via the universal biconditional elimination rule.