mathlib documentation

category_theory.​limits.​types

category_theory.​limits.​types

(internal implementation) the limit cone of a functor, implemented as flat sections of a pi type

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(internal implementation) the fact that the proposed limit cone is the limit

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@[nolint]

A quotient type implementing the colimit of a functor F : J ⥤ Type u, as pairs ⟨j, x⟩ where x : F.obj j, modulo the equivalence relation generated by ⟨j, x⟩ ~ ⟨j', x'⟩ whenever there is a morphism f : j ⟶ j' so F.map f x = x'.

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(internal implementation) the colimit cocone of a functor, implemented as a quotient of a sigma type

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(internal implementation) the fact that the proposed colimit cocone is the colimit

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@[simp]
theorem category_theory.​limits.​types.​colimit_equiv_quot_symm_apply {J : Type u} [category_theory.small_category J] (F : J Type u) (j : J) (x : F.obj j) :
((category_theory.limits.types.colimit_equiv_quot F).symm) (quot.mk (λ (p p' : Σ (j : J), F.obj j), ∃ (f : p.fst p'.fst), p'.snd = F.map f p.snd) j, x⟩) = category_theory.limits.colimit.ι F j x

def category_theory.​limits.​types.​image {α β : Type u} :
β)Type u

the image of a morphism in Type is just set.range f

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the inclusion of image f into the target

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the universal property for the image factorisation

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