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: p_1 -> r_6. u_1. u_1 -> r_6. r_6 -> p.
r_6 can be inferred via the modus ponens rule. p_1 -> p can be inferred via the transitivity rule. u_1 -> p can be inferred via the transitivity rule.