Well, the logic of flow above is also flawed. If GWI = PTSD, it doesn't follow from anywhere that PTSD = CFS/ME, because first you have to prove that GWI is fully equivalent with CFS. Besides, we already have international consensus criteria that classifies diseases based on evidence. In CFS a central criterium is post-exertional malaise (PEM). Just by looking at this one symptom, the absurdity of equating CFS with PTSD becomes clear, or at least I have yet to read that PTSD revolves around post-exterional malaise.