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: S_7(a_7) -> p. ~q_8. p -> q_8. forall x_7: W(x_7) <-> S_7(x_7).
~p can be inferred via the modus tollens rule. S_7(a_7) -> q_8 can be inferred via the transitivity rule. forall x_7: W(x_7) -> S_7(x_7) can be inferred via the universal biconditional elimination rule. forall x_7: S_7(x_7) -> W(x_7) can be inferred via the universal biconditional elimination rule.