Hi, In your order given, we violate rule one because H J K form a consecutive block of three. Our inferences for this to see why H can't go fourth would be: _ _ K H _ _ J can't go second, or fourth, because it can't form a 3 block with K and H. So J would have to go 1 or 6 but it also can't go there by rule 4. So J has nowhere to go and H cannot go fourth.
