CTM has a wonderful premise; and unlike SICP, it does not aim to be freshman text book, and hence can jump headlong into the depth of the matter. Though I could

CTM has a wonderful premise; and unlike SICP, it does not aim to be freshman text book, and hence can jump headlong into the depth of the matter. Though I could'nt progress after a while, when they started to use a difference-list method, to achieve a semblance of stateful behaviour while using a declarative model. I couldn't understand that till until I later studied some Prolog.