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: r_8 <-> q_6. s_4 -> r_8. p_8 -> s_4. ~q_6. r_8 -> p_8.
s_4 -> p_8 can be inferred via the transitivity rule. p_8 -> r_8 can be inferred via the transitivity rule. r_8 -> s_4 can be inferred via the transitivity rule. r_8 -> q_6 can be inferred via the biconditional elimination rule. q_6 -> r_8 can be inferred via the biconditional elimination rule. ~r_8 can be inferred via the biconditional elimination rule.