What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? t_2 <-> u. p_11 -> t_2. u or ~u_3. ~p_11. t_2 -> p_11.
~t_2. u_3 -> u. p_11 <-> t_2. t_2 <-> p_11. t_2 -> u. u -> t_2.