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_1 <-> t. ~p_12. p_12 <-> q_1. ~t -> p.
q_1 -> t can be inferred via the biconditional elimination rule. p_12 -> q_1 can be inferred via the biconditional elimination rule. t -> q_1 can be inferred via the biconditional elimination rule. q_1 -> p_12 can be inferred via the biconditional elimination rule. ~q_1 can be inferred via the biconditional elimination rule.