Anyone else really struggling with 4.b? I can't seem to get my sentence "The head of a horse is the head of an animal", into CNF...
I get to a point where Skolemization can't work since my Existential sentence(the original Universal sentence negated) is not in the scope of a Universal sentence. I've been looking at the logic books I have for COS*61 and it seems I understand Skolemization correctly.
I saw that my problem was that Skolemization *can* work without it being in the scope of a Universal quantification. You just use a constant when in the scope of a Existential quantifier.