iam learning formal schemes. Suppose $Y\subset X$ are schemes, and $\hat{X}$ is the completion of $X$ along closed subscheme $Y$. I wondered if there is a notion of sheaf of differential forms on a formal scheme $\hat{X}$ and a 'de Rham' complex $\Omega^.$ whose cohomology has a relation with cohomology of $X$ or $Y$.
