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: ~q_4. S_7(c_3) <-> q_4. forall x_7: S(x_7) <-> S_7(x_7).
S_7(c_3) -> q_4 can be inferred via the biconditional elimination rule. q_4 -> S_7(c_3) can be inferred via the biconditional elimination rule. ~S_7(c_3) can be inferred via the biconditional elimination rule. forall x_7: S(x_7) -> S_7(x_7) can be inferred via the universal biconditional elimination rule. forall x_7: S_7(x_7) -> S(x_7) can be inferred via the universal biconditional elimination rule.