representable functor
可表函子
Meaning in context
A set-valued functor naturally isomorphic to Hom(-,A) in the contravariant case, or Hom(A,-) in the covariant case.
反变情形自然同构于 Hom(-,A)、或共变情形自然同构于 Hom(A,-) 的集合值函子。
Example
On sets, is represented covariantly by .
Usage and distinctions
A family of bijections without naturality is not a representation.
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Recommended reading in this subject · Preparation & skip guidance
Definition sources
- Emily Riehl — Category Theory in Context (current second-edition draft)§2.1, Definition 2.1.4 · Checked 2026-10-14
Translation sources
- 李文威 — 代数学方法,第一卷(作者源码)第2章,「可表函子」,定义 def:representable-functor · Checked 2026-10-14