T14904a.hs:10:6: error: [GHC-91028]
    • Expected kind ‘forall (a :: k2). g a’, but ‘f’ has kind ‘k1’
      Cannot equate type variable ‘k1’
      with a kind involving polytypes: forall (a :: k2). g a
      ‘k1’ is a rigid type variable bound by
        a family instance declaration
        at T14904a.hs:10:3-30
    • In the first argument of ‘F’, namely ‘(f :: forall a. g a)’
      In the type family declaration for ‘F’