hom-sets (i.e. sets of morphisms between objects) give rise to important functors to the category of sets. These functors are called hom-functors and...
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Yoneda lemma (redirect from Yoneda functor)
called a hom-functor. This functor is denoted: h A = H o m ( A , − ) {\displaystyle h_{A}=\mathrm {Hom} (A,-)} . The (covariant) hom-functor h A {\displaystyle...
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the group homomorphism Hom(f, g): Hom(A2, B1) → Hom(A1, B2) is given by φ ↦ g ∘ φ ∘ f. See Hom functor. Representable functors We can generalize the previous...
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tensor-hom adjunction is that the tensor product − ⊗ X {\displaystyle -\otimes X} and hom-functor Hom ( X , − ) {\displaystyle \operatorname {Hom} (X,-)}...
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Limit (category theory) (redirect from Continuous functor)
from the fact the covariant Hom functor Hom(N, –) : C → Set preserves all limits in C. By duality, the contravariant Hom functor must take colimits to limits...
27 KB (4,330 words) - 23:57, 5 May 2025
of sets. For each object A of C let Hom(A,–) be the hom functor that maps object X to the set Hom(A,X). A functor F : C → Set is said to be representable...
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{\displaystyle \mathrm {hom} _{\mathcal {C}}(Fd,c)} , φ f {\displaystyle \varphi f} is the right adjunct of f {\displaystyle f} (p. 81). The functor F {\displaystyle...
64 KB (10,258 words) - 11:00, 30 April 2025
In mathematics, the Ext functors are the derived functors of the Hom functor. Along with the Tor functor, Ext is one of the core concepts of homological...
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category theory, a faithful functor is a functor that is injective on hom-sets, and a full functor is surjective on hom-sets. A functor that has both properties...
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Presheaf (category theory) (category Functors)
the contravariant hom-functor Hom(–, A) for some object A of C is called a representable presheaf. Some authors refer to a functor F : C o p → V {\displaystyle...
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Thus the contravariant hom-functor changes coproducts into products. Stated another way, the hom-functor, viewed as a functor from the opposite category...
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theory, monoidal functors are functors between monoidal categories which preserve the monoidal structure. More specifically, a monoidal functor between two...
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Closed category (redirect from Internal Hom object)
internal hom [x, y]. Every closed category has a forgetful functor to the category of sets, which in particular takes the internal hom to the external hom. A...
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a branch of mathematics, a functor category D C {\displaystyle D^{C}} is a category where the objects are the functors F : C → D {\displaystyle F:C\to...
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functor is called the internal Hom functor, and the object A ⇒ B {\displaystyle A\Rightarrow B} is called the internal Hom of A {\displaystyle A} and B...
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{\displaystyle \mathrm {Hom} (A\otimes B,C)\cong \mathrm {Hom} (A,B\Rightarrow C).} Here, Hom denotes the (external) Hom-functor of all morphisms in the...
36 KB (5,025 words) - 17:55, 29 March 2025
Enriched category (redirect from Enriched functor)
category, enriched functor, etc... reduce to the original definitions from ordinary category theory. An enriched category with hom-objects from monoidal...
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In mathematics, certain functors may be derived to obtain other functors closely related to the original ones. This operation, while fairly abstract, unifies...
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exact functors are the Hom functors: if A is an abelian category and A is an object of A, then FA(X) = HomA(A,X) defines a covariant left-exact functor from...
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product and the Hom functor are adjoint; however, they might not always lift to an exact sequence. This leads to the definition of the Tor functor and the Ext...
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2-category (redirect from Lax functor)
objects a and b the hom-set Hom ( a , b ) {\displaystyle \operatorname {Hom} (a,b)} acquires a structure of a category as a functor category. A vertical...
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Six operations (redirect from Six functors)
internal tensor product internal Hom The functors f ∗ {\displaystyle f^{*}} and f ∗ {\displaystyle f_{*}} form an adjoint functor pair, as do f ! {\displaystyle...
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specifically in the area of category theory, a forgetful functor (also known as a stripping functor) "forgets" or drops some or all of the input's structure...
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polynomial functor if the following equivalent conditions hold: For every pair of vector spaces X, Y in V {\displaystyle {\mathcal {V}}} , the map F : Hom (...
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Preadditive category (redirect from Additive functor)
considering functors between two R-linear categories, one often restricts to those that are R-linear, so those that induce R-linear maps on each hom-set. Any...
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reformulate. With it came the idea that the 'real' tensor product and Hom functors would be those existing on the derived level; with respect to those,...
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France Hom, Šentrupert, a dispersed settlement in Slovenia Hom-e Khosrow, a village in Iran Hom bundle, in topology Hom functor, in category theory Hom (...
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{\displaystyle F:\mathrm {Hom} _{\mathbf {Vect} }(T,U)\rightarrow \mathrm {Hom} _{\mathbf {Vect} }(F(T),F(U)),} where Hom is notation for Hom functor. If this map...
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Free object (redirect from Free functor)
called the free functor is a left adjoint to the faithful functor U; that is, there is a bijection Hom S e t ( X , U ( B ) ) ≅ Hom C ( F ( X ) , B...
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Loop space (redirect from Loop functor)
computer science is currying, where the cartesian product is adjoint to the hom functor.) Informally this is referred to as Eckmann–Hilton duality. The loop...
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