Cochain homotopy
= Cochain homotopy
For cochain maps $f,g:C^\bullet\to D^\bullet$, a cochain homotopy is a family $K:C^q\to D^{q-1}$ satisfying
$$
f-g=dK+Kd.
$$
Cochain-homotopic maps induce the same map on <cohomology>.
= Cochain homotopy
For cochain maps $f,g:C^\bullet\to D^\bullet$, a cochain homotopy is a family $K:C^q\to D^{q-1}$ satisfying
$$
f-g=dK+Kd.
$$
Cochain-homotopic maps induce the same map on <cohomology>.