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: W(x) <-> R_1(x). r -> W(f). R_1(f).
exists x: R_1(x) can be inferred via the existential generalization rule. forall x: W(x) -> R_1(x) can be inferred via the universal biconditional elimination rule. forall x: R_1(x) -> W(x) can be inferred via the universal biconditional elimination rule.