What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? ~u_2. u_2 <-> q_7. ~q_11. t -> q_11.
~t. ~u_2 and ~q_11. ~q_11 and ~u_2. u_2 -> q_7. q_7 -> u_2. ~q_7.