An Introduction to Homological Algebra
《An Introduction to Homological Algebra》 · 第 18 页 · Section 1.5.1
For a chain map \(f:B_\bullet\to C_\bullet\), its mapping cone \(\operatorname{cone}(f)\) has degree \(n\) part \(B_{n-1}\oplus C_n\) and differential \(d(b,c)=(-d(b),d(c)-f(b))\).