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: q_8 <-> q. ~t. q_2 <-> q_8. q_2 <-> t.
q_8 -> q can be inferred via the biconditional elimination rule. q_2 -> q_8 can be inferred via the biconditional elimination rule. q_2 -> t can be inferred via the biconditional elimination rule. q -> q_8 can be inferred via the biconditional elimination rule. q_8 -> q_2 can be inferred via the biconditional elimination rule. t -> q_2 can be inferred via the biconditional elimination rule. ~q_2 can be inferred via the biconditional elimination rule.