Algebraic Topology
《Algebraic Topology》 · 第 461 页 · Section 4.3
For a cofibration \(A\hookrightarrow B\), the quotient \(B/A\) is its cofiber. Replacing an arbitrary map \(f:A\to B\) by the cofibration \(A\hookrightarrow M_f\), its cofiber is the mapping cone \(C_f=M_f/(A\times\{0\})\).