Interactive code snippets not yet available for SoH 2.0, see our Status of of School of Haskell 2.0 blog post bound provides a powerful but simple toolbox for dealing with capture-avoiding substitution in your code. It lets you use classes you already know: Monad, Foldable and Traversable to manipulate your syntax tree, and it factors out issues of name capture into a reusable monad transformer na