T14584.hs:57:41: warning: [GHC-39999] [-Wdeferred-type-errors (in -Wdefault)]
    • Could not deduce ‘SingI a’ arising from a use of ‘sing’
      from the context: (Action act, Monoid a, Good m)
        bound by the instance declaration at T14584.hs:55:10-89
    • In the second argument of ‘fromSing’, namely
        ‘(sing @m @a :: Sing _)’
      In the fourth argument of ‘act’, namely
        ‘(fromSing @m (sing @m @a :: Sing _))’
      In the expression:
        act @_ @_ @act (fromSing @m (sing @m @a :: Sing _))

T14584.hs:57:50: warning: [GHC-25897] [-Wdeferred-type-errors (in -Wdefault)]
    • Could not deduce ‘m ~ *’
      from the context: (Action act, Monoid a, Good m)
        bound by the instance declaration at T14584.hs:55:10-89
      ‘m’ is a rigid type variable bound by
        the instance declaration
        at T14584.hs:55:10-89
    • In the type ‘a’
      In the second argument of ‘fromSing’, namely
        ‘(sing @m @a :: Sing _)’
      In the fourth argument of ‘act’, namely
        ‘(fromSing @m (sing @m @a :: Sing _))’

T14584.hs:57:60: warning: [GHC-88464] [-Wpartial-type-signatures (in -Wdefault)]
    • Found type wildcard ‘_’ standing for ‘a :: m’
      Where: ‘a’, ‘m’ are rigid type variables bound by
               the instance declaration
               at T14584.hs:55:10-89
    • In the first argument of ‘Sing’, namely ‘_’
      In an expression type signature: Sing _
      In the second argument of ‘fromSing’, namely
        ‘(sing @m @a :: Sing _)’
    • Relevant bindings include
        monHom :: a -> a (bound at T14584.hs:57:3)