《一般拓扑学基础》
· 第 319 页 · Definition
In a category with finite coproducts and an initial object, a cogroup object is an object \(C\) with comultiplication \(m:C\to C\amalg C\), coinverse \(h:C\to C\), and counit \(e:C\to A\) satisfying the dual group diagrams.
