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: ~R_17(a_17). forall x_17: R_17(x_17) -> S_17(x_17). u_2 <-> R_17(a_17). S_17(a_17) -> u_2.
u_2 -> R_17(a_17) can be inferred via the biconditional elimination rule. R_17(a_17) -> u_2 can be inferred via the biconditional elimination rule.