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_1 <-> Q_3(a_19). q -> q_1. forall x_19: Q_3(x_19) -> S_19(x_19). ~S_19(a_19).
q_1 -> Q_3(a_19) can be inferred via the biconditional elimination rule. Q_3(a_19) -> q_1 can be inferred via the biconditional elimination rule.