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: w <-> q_8. p_1 <-> u. ~w. p_1 -> q_8.
w -> q_8 can be inferred via the biconditional elimination rule. p_1 -> u can be inferred via the biconditional elimination rule. q_8 -> w can be inferred via the biconditional elimination rule. u -> p_1 can be inferred via the biconditional elimination rule. ~q_8 can be inferred via the biconditional elimination rule.