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 y: ~U(y). forall y: U(y) <-> R(y). forall y: R(y) <-> U(y).
forall y: U(y) -> R(y) can be inferred via the universal biconditional elimination rule. forall y: R(y) -> U(y) can be inferred via the universal biconditional elimination rule. forall y: R(y) -> U(y) can be inferred via the universal biconditional elimination rule. forall y: U(y) -> R(y) can be inferred via the universal biconditional elimination rule. forall y: ~R(y) can be inferred via the universal biconditional elimination rule. forall y: ~R(y) can be inferred via the universal biconditional elimination rule.