categorical coproduct
余积
Meaning in context
An object with maps from a specified family such that each family of maps into any Y extends uniquely to a map from that object to Y.
配有从指定对象族进入的态射的对象,使到任意 Y 的对应态射族都唯一延拓为从该对象到 Y 的态射。
Example
is a two-element coproduct in sets.
Usage and distinctions
Ordinary union of overlapping sets fails to retain independent maps out of each component.
Recommended reading in this subject · Preparation & skip guidance
Definition sources
- Emily Riehl — Category Theory in Context (current second-edition draft)§3.1, Definition 3.1.23 · Checked 2026-10-14
Translation sources
- 李文威 — 代数学方法,第一卷(作者源码)第2章,「极限」,有限极限讨论,积与余积的第一项「余积」 · Checked 2026-10-14