Chain subcomplex
= Chain subcomplex
A chain subcomplex $D_\bullet\subseteq C_\bullet$ consists of subgroups $D_i\leq C_i$ preserved by the <boundary operator>: $\partial(D_i)\subseteq D_{i-1}$.
= Chain subcomplex
A chain subcomplex $D_\bullet\subseteq C_\bullet$ consists of subgroups $D_i\leq C_i$ preserved by the <boundary operator>: $\partial(D_i)\subseteq D_{i-1}$.