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: q_1. ~R_13(i). forall x_13: R_13(x_13) <-> S_13(x_13).
q_1 and ~R_13(i) can be inferred via the conjunction rule. ~R_13(i) and q_1 can be inferred via the conjunction rule. forall x_13: R_13(x_13) -> S_13(x_13) can be inferred via the universal biconditional elimination rule. forall x_13: S_13(x_13) -> R_13(x_13) can be inferred via the universal biconditional elimination rule.