srmico

File: [functional-programming-lean/src/monad-transformers.md](https://github.com/leanprover/fp-lean/blob/master/functional-programming-lean/src/monad-transformers.md) Sentence: "A concrete monad can be build from a collection of monad transformers, which enables much more code re-use." Word "build" should be "built" Awesome book btw!