一般拓扑学基础 张德学 《一般拓扑学基础》 · 第 55 页 · Definition A pointed space \((X,x_0)\) is an H-space if there is a pointed map \(m:X\times X\to X\) such that \(m(x_0,-)\) and \(m(-,x_0)\) are homotopic to \(\operatorname{id}_X\) relative to \(x_0\). 查看原书页面
