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 <-> t. ~r. u <-> t. q.
~r and q can be inferred via the conjunction rule. q and ~r can be inferred via the conjunction rule. r -> t can be inferred via the biconditional elimination rule. u -> t can be inferred via the biconditional elimination rule. t -> r can be inferred via the biconditional elimination rule. t -> u can be inferred via the biconditional elimination rule. ~t can be inferred via the biconditional elimination rule.