T5300.hs:11:7:
    Could not deduce (C1 a b c0)
      arising from the ambiguity check for `f1'
    from the context (Monad m, C1 a b c)
      bound by the type signature for
                 f1 :: (Monad m, C1 a b c) => a -> StateT (T b) m a
      at T5300.hs:11:7-50
    The type variable `c0' is ambiguous
    In the ambiguity check for:
      forall a b (m :: * -> *) c.
      (Monad m, C1 a b c) =>
      a -> StateT (T b) m a
    In the type signature for `f1':
      f1 :: (Monad m, C1 a b c) => a -> StateT (T b) m a

T5300.hs:14:7:
    Could not deduce (C1 a1 b1 c10)
      arising from the ambiguity check for `f2'
    from the context (Monad m, C1 a1 b1 c1, C2 a2 b2 c2)
      bound by the type signature for
                 f2 :: (Monad m, C1 a1 b1 c1, C2 a2 b2 c2) =>
                       a1 -> StateT (T b2) m a2
      at T5300.hs:14:7-69
    The type variable `c10' is ambiguous
    In the ambiguity check for:
      forall a1 b2 (m :: * -> *) a2 b1 c1 c2.
      (Monad m, C1 a1 b1 c1, C2 a2 b2 c2) =>
      a1 -> StateT (T b2) m a2
    In the type signature for `f2':
      f2 :: (Monad m, C1 a1 b1 c1, C2 a2 b2 c2) =>
            a1 -> StateT (T b2) m a2