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: ~u. ~p_7. p_11 -> u. p_7 <-> r.
~p_11 can be inferred via the modus tollens rule. ~u and ~p_7 can be inferred via the conjunction rule. ~p_7 and ~u can be inferred via the conjunction rule. p_7 -> r can be inferred via the biconditional elimination rule. r -> p_7 can be inferred via the biconditional elimination rule. ~r can be inferred via the biconditional elimination rule.