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_12 -> w_1. u_2 <-> q_12. forall x_26: P_26(x_26). P_26(a_26) -> q_12.
P_26(a_26) -> w_1 can be inferred via the transitivity rule. u_2 -> q_12 can be inferred via the biconditional elimination rule. q_12 -> u_2 can be inferred via the biconditional elimination rule.