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: P_3(f) <-> w_1. w_1 or W_3(f). forall x: W_3(x) -> P_3(x).
R_1(f) -> w_1 can be inferred via the rewriting rule. P_3(f) -> w_1 can be inferred via the biconditional elimination rule. w_1 -> P_3(f) can be inferred via the biconditional elimination rule.