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: ~T_1(a_11). forall x_11: T_1(x_11) <-> S_11(x_11). p_15 or r. ~p_15.
r can be inferred via the disjunctive syllogism rule. ~T_1(a_11) and ~p_15 can be inferred via the conjunction rule. ~p_15 and ~T_1(a_11) can be inferred via the conjunction rule. forall x_11: T_1(x_11) -> S_11(x_11) can be inferred via the universal biconditional elimination rule. forall x_11: S_11(x_11) -> T_1(x_11) can be inferred via the universal biconditional elimination rule.