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_4(f). forall y: P_1(y) <-> R_4(y).
forall y: P_1(y) -> R_4(y) can be inferred via the universal biconditional elimination rule. forall y: R_4(y) -> P_1(y) can be inferred via the universal biconditional elimination rule.