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_6 -> q. s -> q_6. q <-> s.
s -> q can be inferred via the transitivity rule. q -> s can be inferred via the biconditional elimination rule. s -> q can be inferred via the biconditional elimination rule.