- | WpApp Var -- [] x; the xi are dicts or coercions
- | WpTyApp Type -- [] t
- | WpLam Id -- \x. []; the xi are dicts or coercions
- | WpTyLam TyVar -- \a. []
+ | WpApp Var -- [] d the 'd' is a type-class dictionary
+ | WpTyApp Type -- [] t the 't' is a type or corecion
+ | WpLam Id -- \d. [] the 'd' is a type-class dictionary
+ | WpTyLam TyVar -- \a. [] the 'a' is a type or coercion variable