Switching subtopics to the "Chirality" section, ...
I take Ben's point (with which I agree) to be that "Chirality" is an even more obscure word than "Endomorphism". (Except perhaps in the realm of subatomic particle physics.) Grokking this material is hard enough without having to reach for a dictionary. If you mean 'left-biased' vs 'right-biased', or 'from-front' vs 'from-rear' or 'Cons-oriented' vs 'Snoc-oriented', say that. (And I'll be interested to see how anyone explains this without `fromList` jigging their elbow.) Now I can see Foldable structures are abstract, not spatial. But Cons is recursive on its (textually) right operand, whereas `Bin` or `Node` are symmetric between their (textually) left/right recursive operands. I guessed that's what the Chirality section was talking about, so I skimmed the first sentence and skipped on.