category-theory

问题 Control.Category.Constrained is a very interesting project that presents the class for cartesian closed categories - Curry. Yet, I do not see why we think of all cartesian closed categories which allow curry and uncurry ( Hom(X * Y, Z) ≅ Hom(X, Z^Y) in terms of category theory). Wikipedia says that such property holds only for locally small cartesian closed categories. Under this post many people suggest that Hask itself is not locally small (on the other hand, everyone says that Hask is not

问题 Control.Category.Constrained is a very interesting project that presents the class for cartesian closed categories - Curry. Yet, I do not see why we think of all cartesian closed categories which allow curry and uncurry ( Hom(X * Y, Z) ≅ Hom(X, Z^Y) in terms of category theory). Wikipedia says that such property holds only for locally small cartesian closed categories. Under this post many people suggest that Hask itself is not locally small (on the other hand, everyone says that Hask is not

问题 In Control.Arrow.Constrained there is a class WellPointed: Unlike with Morphism and PreArrow, a literal dual of WellPointed does not seem useful. Which is true as the duality for the following methods seems a bit weird: globalElement :: ObjectPoint a x => x -> a (UnitObject a) x unit :: CatTagged a (UnitObject a) const :: (Object a b, ObjectPoint a x) => x -> a b x But why would not we like (for example) having const for "choice" arrows (like having some constant error information which could

问题 Since this is (at least it seems to me) tightly related to programming, I'm asking here rather than on math or cs, but if you it think it best fits there or in another side, please just give your opinion. At the end of Chapter 2 of Bartosz Milewski's Category Theory for Programmers , there's this question: How many different functions are there from Bool to Bool ? Can you implement them all? This is my reasoning: Bool has only two elements in it, True and False ; different refers to what the

来源： https://stackoverflow.com/questions/63639328/how-is-arr-fst-a-natural-transformation

来源： https://stackoverflow.com/questions/63639328/how-is-arr-fst-a-natural-transformation

来源： https://stackoverflow.com/questions/63639328/how-is-arr-fst-a-natural-transformation

来源： https://stackoverflow.com/questions/54261967/what-is-representable-used-for-in-haskell

来源： https://stackoverflow.com/questions/54261967/what-is-representable-used-for-in-haskell

来源： https://stackoverflow.com/questions/64394487/if-either-can-be-either-left-or-right-but-not-both-then-why-does-it-correspond