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.
Preadditive category
Definition
A category (Category, object, morphism, domain, codomain, identity, composition, and hom-collection) is preadditive when every hom-set is an abelian group and composition is bilinear in the sense that for all composable morphisms , , and ,
The additive identity in is written and is called the zero element of that hom-group.
Depends on
Used by
- Additive category Definition
- Additive functor Definition
- The idempotent completion of a preadditive category Definition
- A preadditive category with two objects and a nonzero hom-group Example
- FALSE: a preadditive category with a zero object must have binary biproducts False statement
- A small product of preadditive categories is preadditive Proposition
- Additive functors and natural transformations form a preadditive category Proposition
- An additive functor preserves zero morphisms Proposition
- In a preadditive category with a zero object, the zero morphism is the neutral element of each hom-group Proposition
- A one-object preadditive category is the same thing as a ring Theorem
- A semiadditive category is preadditive exactly when every morphism has an additive inverse Theorem
- In a preadditive category with a zero object, a morphism is monic exactly when its kernel is zero Theorem
- In a preadditive category, a finite product is automatically a biproduct Theorem
- In a preadditive category, an object is initial exactly when it is terminal Theorem
- In a preadditive category, the equalizer of a parallel pair is the kernel of their difference Theorem
- The hom-bifunctor of a preadditive category takes values in abelian groups Theorem
- The opposite of a preadditive category is preadditive Theorem
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
- Kiran S. Kedlaya, Solid modules over an ordinary ring, Definition 1.2.1 (standard reference, not scraped)
- The Stacks Project, Section 12.3, Definition 12.3.1 (standard reference, not scraped)