What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? p_2 -> ~t. r_2 -> u_3. u_3 -> r_2. t. p_2 <-> r_2. q_2.
~p_2. t and q_2. q_2 and t. r_2 <-> u_3. u_3 <-> r_2. p_2 -> r_2. r_2 -> p_2.