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: ~t. q -> r. t <-> q. q or ~r.
r -> q can be inferred via the rewriting rule. t -> q can be inferred via the biconditional elimination rule. q -> t can be inferred via the biconditional elimination rule. ~q can be inferred via the biconditional elimination rule.