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 x_15: R_15(x_15) -> S_15(x_15). r_2 -> p_1. p_1 -> R_15(e). S_15(e) -> r_6.
r_2 -> R_15(e) can be inferred via the transitivity rule.