Consider the following premises. R(c) -> u. forall y_4: R(y_4). R(c) or ~u. Can we infer u from them?
 From forall y_4: R(y_4) we can infer R(c). From R(c) or ~u we can infer u -> R(c). From u -> R(c), R(c) -> u we can infer u <-> R(c). From u <-> R(c) we can infer R(c) -> u. Finally, from R(c) -> u, R(c) we can infer u. Therefore, the answer is yes.