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: forall x_19: R_19(x_19) -> S_19(x_19). S_19(a_19) <-> w_2. ~w_2.
S_19(a_19) -> w_2 can be inferred via the biconditional elimination rule. w_2 -> S_19(a_19) can be inferred via the biconditional elimination rule. ~S_19(a_19) can be inferred via the biconditional elimination rule.