Consider the following premises. exists y: W_4(y). forall y: Q(y). Can we infer forall y: ~W_4(y) from them? If possible, name the inference rules being used at each step.
 From forall y: Q(y), exists y: W_4(y) we can infer exists y: Q(y) and W_4(y) via existential conjunction. Finally, from exists y: Q(y) and W_4(y) we can infer exists y: Q(y) via existential simplification, which contradicts forall y: ~W_4(y). Therefore, the answer is no.