diff --git a/effect-monad.cabal b/effect-monad.cabal
--- a/effect-monad.cabal
+++ b/effect-monad.cabal
@@ -1,5 +1,5 @@
 name:                   effect-monad
-version:                0.8.0.0
+version:                0.8.1.0
 synopsis:               Embeds effect systems and program logics into Haskell using graded monads and parameterised monads
 description:
    Provides the graded monad structure to Haskell via Control.Effect
diff --git a/examples/Inc.hs b/examples/Inc.hs
new file mode 100644
--- /dev/null
+++ b/examples/Inc.hs
@@ -0,0 +1,35 @@
+{-# LANGUAGE ConstraintKinds #-}
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE DeriveFunctor #-}
+{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE GADTs #-}
+{-# LANGUAGE KindSignatures #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE PolyKinds #-}
+{-# LANGUAGE RankNTypes #-}
+{-# LANGUAGE RebindableSyntax #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE TemplateHaskell #-}
+{-# LANGUAGE TypeFamilies #-}
+{-# LANGUAGE TypeOperators #-}
+{-# LANGUAGE TypeSynonymInstances #-}
+module EffectsInHaskellProblem where
+
+import           Control.Effect
+import           Control.Effect.State
+import           GHC.TypeLits
+import           Prelude               hiding (log, Monad(..), (>>))
+
+varX :: Var "x"
+varX = Var
+
+inc :: State '["x" :-> Int :! 'RW] ()
+inc =
+    get varX >>= (put varX . (+1))
+
+-- No instance for (Control.Effect.State.Nubable '["x" :-> (Int :! 'W)] '[])
+inc2 =
+    inc >>=
+    \_ ->
+         inc
diff --git a/examples/Reader.hs b/examples/Reader.hs
--- a/examples/Reader.hs
+++ b/examples/Reader.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE ImplicitParams, DataKinds, RebindableSyntax, TypeOperators, ScopedTypeVariables #-}
+{-# LANGUAGE ImplicitParams, DataKinds, RebindableSyntax, TypeOperators, ScopedTypeVariables, FlexibleContexts #-}
 import Prelude hiding (Monad(..))
 import Control.Effect
 import Control.Effect.Reader
diff --git a/examples/State.hs b/examples/State.hs
--- a/examples/State.hs
+++ b/examples/State.hs
@@ -1,15 +1,19 @@
-{-# LANGUAGE DataKinds, RebindableSyntax, TypeOperators, FlexibleInstances #-}
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE RebindableSyntax #-}
+{-# LANGUAGE TypeOperators #-}
+{-# LANGUAGE FlexibleInstances #-}
 
 import Prelude hiding (Monad(..))
 import Control.Effect
 import Control.Effect.State
 
-x_var = Var::(Var "x")
-y_var = Var::(Var "y")
+x_var = Var @ "x"
+y_var = Var @ "y"
 
 {- Computation with a read effect on variable "x" and a
    read-write (update) effect on variable "y" -}
--- example :: State '["x" :-> Int :! R, "y" :-> [Int] :! RW] [Int]
+
+example :: State '["x" :-> Int :! R, "y" :-> [Int] :! RW] [Int]
 example = do
   x <- get x_var
   y <- get y_var
diff --git a/examples/WriterM.hs b/examples/WriterM.hs
new file mode 100644
--- /dev/null
+++ b/examples/WriterM.hs
@@ -0,0 +1,17 @@
+{-# LANGUAGE FlexibleInstances #-}
+
+import Data.Monoid
+
+data Writer w a = Writer { runWriter :: (a, w) }
+
+instance Monoid w => Monad (Writer w) where
+   return a = Writer (a, mempty)
+   (Writer (a, w)) >>= k = let (b, w') = runWriter (k a)
+                           in Writer (b, w `mappend` w')
+
+instance Monad (Writer (Maybe a)) where
+   return a = Writer (a, Nothing)
+   (Writer (a, w)) >>= k = let (b, w') = runWriter (k a)
+                           in case w' of 
+                                Nothing -> Writer (b, w)
+                                Just w' -> Writer (b, Just w')
diff --git a/src/Control/Effect/ParameterisedAsGraded.hs b/src/Control/Effect/ParameterisedAsGraded.hs
--- a/src/Control/Effect/ParameterisedAsGraded.hs
+++ b/src/Control/Effect/ParameterisedAsGraded.hs