I'm stuck on a problem, because I don't know what it means:
Define a distribution $D$ by:
$\omega_1 =0, ... \omega_n =0$
Where the $\omega_i$ is the dual co-frames forms, from the Equations of Structure.
This definition is equivalent to some definition by the Ker of some aplication? Exist a standard argument to prove that $D$ is integrable and parallel?
Thanks!