Tag: lambda-calculus

6 From this Haskell Cafe post, and borrowing some code examples from jyp, we can construct a simple PHOAS evaluator in Haskell as: {-# LANGUAGE GADTs #-} {-# LANGUAGE RankNTypes #-} import Data.Char data Term v t where Var :: v t -> Term v t App :: Term v (a -> b) -> Term…