You had a look at Hoogle? https://hoogle.haskell.org/ https://hoogle.haskell.org/ For some type signatures there is (are) only one (or only a few) meaningful

You had a look at Hoogle? https://hoogle.haskell.org/ https://hoogle.haskell.org/ For some type signatures there is (are) only one (or only a few) meaningful implementation(s).