T14498.hs:32:48: error:
    • Pattern synonym existential ‘kk’ cannot be used here
        (the existential variables of a pattern synonym
         signature do not scope over the pattern)
    • In the kind ‘kk -> k'’
      In the first argument of ‘TypeRep’, namely ‘(a :: kk -> k')’
      In the type ‘TypeRep (a :: kk -> k')’