DefinitionDefinition: Literature-sourcedProof: Not applicableSession-authored (Fable 5 assisted)judge pass (deepseek-v4-pro + claude-sonnet-5)audited 2026-08-17
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.
Algebra and algebra homomorphism for a monad
Definition
Let be a monad on (Monad on a category). A -algebra is an object together with a morphism , called its structure map, satisfying
For -algebras and , a -algebra homomorphism is a morphism in such that
Depends on
Used by
- Algebras for a preorder monad are exactly its fixed objects up to preorder equivalence; on a poset they are its fixed points Corollary
- Free algebra for a monad Definition
- For a group G the monad G×(-) on sets has the G-sets as its algebras Example
- A distributive law makes the composite endofunctor a monad Theorem
- A monad morphism induces restriction of algebras and a natural comparison of free algebras Theorem
- Algebra homomorphisms are closed under identities and composition Theorem
- Algebras for an idempotent monad form a reflective subcategory Theorem
- Algebras for the covariant power-set monad are posets with all small suprema and their morphisms preserve every small supremum Theorem
- Every monadic functor is conservative Theorem
Dependency tree · next 3 levels
Direct dependencies and their dependencies through the next three levels: 6 results over 6 levels. An arrow runs from a result to what uses it, and this result sits at the bottom with a heavier outline. Click the chart to enlarge it.
Sources
- E. Riehl, Category Theory in Context, 2nd ed., Definition 5.2.4 (standard reference, not scraped)
- B. Richter, From Categories to Homotopy Theory, Definition 6.2.1 (standard reference, not scraped)