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 x_4: U_3(x_4). p_4 <-> U_3(j_2).
p_4 -> U_3(j_2) can be inferred via the biconditional elimination rule. U_3(j_2) -> p_4 can be inferred via the biconditional elimination rule.