Consider the following premises. R_4(g) -> p_4. p_4 <-> S_8(g). forall x_8: R_4(x_8) or S_8(x_8). Can we infer p_4 from them?
 From forall x_8: R_4(x_8) or S_8(x_8) we can infer R_4(g) or S_8(g). From p_4 <-> S_8(g) we can infer S_8(g) -> p_4. Finally, from R_4(g) -> p_4, S_8(g) -> p_4, R_4(g) or S_8(g) we can infer p_4. Therefore, the answer is yes.