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: U(a_16) <-> p. forall x_16: U(x_16) and S_16(x_16).
U(a_16) -> p can be inferred via the biconditional elimination rule. p -> U(a_16) can be inferred via the biconditional elimination rule. forall x_16: U(x_16) can be inferred via the universal simplification rule. forall x_16: S_16(x_16) can be inferred via the universal simplification rule.