Differential Forms in Algebraic Topology
《Differential Forms in Algebraic Topology》 · 第 259 页 · Section 19
A differential graded algebra \(\mathcal M\) is a minimal model for \(A\) if \(\mathcal M\) is free, there is a chain map \(\mathcal M\to A\) inducing an isomorphism in cohomology, and the differential of each generator is zero or decomposable.