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: w. p_12 or q_6. q_6 -> t_4. p_12 <-> t_4.
p_12 -> t_4 can be inferred via the biconditional elimination rule. t_4 -> p_12 can be inferred via the biconditional elimination rule.