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: t. S_1(f) -> ~t. forall z: Q(z) <-> S_1(z).
~S_1(f) can be inferred via the modus tollens rule. forall z: Q(z) -> S_1(z) can be inferred via the universal biconditional elimination rule. forall z: S_1(z) -> Q(z) can be inferred via the universal biconditional elimination rule.