How statement and proof provenance work
The first chip identifies the source of the statement or construction; the second identifies the source of its local proof or verification.
- Literature-sourced: the exact statement appears in a cited source; only wording and notation differ.
- AI-adapted: a semantically identical restatement of literature-sourced material, modulo indexing, notation, and boundary cases adopted by the library.
- AI-generated: a genuinely novel statement formulated by AI, with no source for the claim itself.
These labels describe origin, not correctness: citations and verification chips remain separate evidence.
Natural transformation and its components
Definition
Let be functors (Covariant functor, identity functor, composite functor, and contravariant functor). A natural transformation is a family of morphisms , one for each object of , such that every satisfies the naturality equation
The morphism is the component of at .
Depends on
Used by
- A componentwise family between functors need not be a natural transformation Counterexample
- A componentwise family of morphisms need not be a natural transformation and hence need not be a unit Counterexample
- A balanced derived bifunctor Definition
- Canonical morphisms between parenthesised tensor words Definition
- Codensity monad Definition
- Constant diagrams, cones, cocones, and their morphisms Definition
- Dinatural transformation between functors on CᵒᵖtimesC Definition
- Functor category [C,D] Definition
- Identity natural transformation and vertical composition Definition
- Lax, strong, and strict monoidal functors Definition
- Left and right Kan extensions Definition
- Local systems and pullback Definition
- Monad on a category Definition
- Monoidal natural transformation Definition
- Morphism of cohomological delta functors Definition
- Morphism of homological delta functors Definition
- Morphisms between monads on one category Definition
- Morphisms of presheaves Definition
- Natural isomorphism Definition
- Presheaves, covariantly and contravariantly representable functors, and representations Definition
- Set-weighted limits and colimits Definition
- Stable natural cohomology operation Definition
- The category of right-module endofunctors Definition
- Whiskering and horizontal composition of natural transformations Definition
- A weighted limit computing a kernel pair Example
- For a monoid action, Yoneda says that an equivariant map from the regular action is determined by the identity element Example
- For n≥ 1, determinant is a natural transformation det:GLₙ(-)⟹(-)^× from commutative rings to groups Example
- Singletons define a natural transformation from the identity functor on sets to the covariant power-set functor Example
- The end formula checked by hand against natural transformations on the walking arrow Example
- A natural transformation is determined by its component at one object False statement
- FALSE: every weighted limit is the ordinary limit of the diagram it weights False statement
- A partial morphism of delta functors extends through one dimension shift Lemma
- Evaluation at the identity gives Nat(C(a,-),F)≅ F(a) and proves that the natural-transformation collection is a set Lemma
- A natural transformation induces natural transformations of left derived functors Proposition
- A natural transformation induces natural transformations of right derived functors Proposition
- A weighted limit of a set-valued diagram is the set of natural transformations from the weight Proposition
- Composing a dinatural transformation with a natural transformation on either side gives a dinatural transformation Proposition
- A family into a parametrised end is natural, or dinatural, in the parameter exactly when its composite with the counit is Theorem
- A monad morphism induces restriction of algebras and a natural comparison of free algebras Theorem
- A natural transformation of functors induces a unique morphism of their ends and of their coends Theorem
…and 8 more results.
Dependency tree · two levels
3 results within two dependency steps of this one, each drawn at its shortest distance from it. An arrow runs from a result to what uses it, so the chart reads left to right and ends at this result, which carries a heavier outline. Every node is a link to that result. Click elsewhere on the chart to enlarge it.
Sources
- Emily Riehl, Category Theory in Context, Chapter 1 (standard reference, not scraped)