Consider the following premises. R_13(a_12). forall x_13: P_13(x_13) -> Q_13(x_13). R_13(a_12) -> P_13(a_12). forall x_13: Q_13(x_13) -> R_13(x_13). Can we infer ~r from them? If possible, name the inference rules being used at each step.
We cannot infer that from the premises. Therefore the answer is no.