Expand on the 📝 for eval to mention the open-recursive child term evaluator.

src/Data/Abstract/Eval.hs

@@ -20,7 +20,7 @@ import Prelude hiding (fail)
 
 -- | The 'Eval' class defines the necessary interface for a term to be evaluated. While a default definition of 'eval' is given, instances with computational content must implement 'eval' to perform their small-step operational semantics.
 class Monad m => Eval term v m constr where
-  -- | Evaluate a term.
+  -- | Evaluate a term using an open-recursive evaluator for any child terms.
   eval :: ((v -> m v) -> term -> m v) -> ((v -> m v) -> constr term -> m v)
 
   default eval :: (MonadFail m, Show1 constr) => ((v -> m v) -> term -> m v) -> ((v -> m v) -> constr term -> m v)