Consider the following premises. exists z_4: W_2(z_4). forall z_4: U_4(z_4). Can we infer exists z_4: U_4(z_4) and W_2(z_4) from them? If possible, name the inference rules being used at each step.
We can infer exists z_4: U_4(z_4) and W_2(z_4) via the existential conjunction rule. Therefore, the answer is yes.