Class Field Theory
《Class Field Theory》 · 第 118 页 · Definition 4.32
A path-connected space \(X\) is an Eilenberg–Mac Lane space of type \((G,n)\), denoted \(K(G,n)\), if \(\pi_j(X)\cong G\) for \(j=n\) and \(\pi_j(X)=0\) for \(j\ne n\).