Some background for the uninitiated, this is Lambda Man, or Philip Wadler. One of the core contributors to Haskell. He also introduced monads to Haskell, which

Some background for the uninitiated, this is Lambda Man, or Philip Wadler. One of the core contributors to Haskell. He also introduced monads to Haskell, which has had a huge impact on functional programming in general (https://ncatlab.org/nlab/files/WadlerMonads.pdf https://ncatlab.org/nlab/files/WadlerMonads.pdf). His home page has so many functional programming treasures: http://homepages.inf.ed.ac.uk/wadler/ http://homepages.inf.ed.ac.uk/wadler/. His most recent book is "Programming Language Foundations in Agda", which is available for free: https://plfa.github.io/ https://plfa.github.io/. I have no affiliation, just a fan.