Cochain complex
= Cochain complex
{title2=$(C^\bullet,d)$}
{wiki}
A cochain complex is a sequence of abelian groups or modules and maps $d^n:C^n\to C^{n+1}$ satisfying $d^{n+1}d^n=0$. Its cohomology is $H^n(C)=\ker d^n/\operatorname{im}d^{n-1}$.
= Cochain complex
{title2=$(C^\bullet,d)$}
{wiki}
A cochain complex is a sequence of abelian groups or modules and maps $d^n:C^n\to C^{n+1}$ satisfying $d^{n+1}d^n=0$. Its cohomology is $H^n(C)=\ker d^n/\operatorname{im}d^{n-1}$.