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 z_3: R_2(z_3) or P(z_3). P(c_1) -> q. q <-> R_2(c_1).
q -> R_2(c_1) can be inferred via the biconditional elimination rule. R_2(c_1) -> q can be inferred via the biconditional elimination rule.