diff --git a/mealy.cabal b/mealy.cabal
--- a/mealy.cabal
+++ b/mealy.cabal
@@ -1,7 +1,8 @@
 cabal-version: 2.4
 name:          mealy
-version:       0.0.2
+version:       0.0.3
 synopsis: See readme.md
+
 description: See readme.md for description.
 category: project
 author: Tony Day
@@ -20,17 +21,14 @@
     src
   build-depends:
     adjunctions >= 4.4,
-    backprop >= 0.2.6.4 && < 0.3,
     base >=4.7 && <5,
     containers >= 0.6,
     folds,
     generic-lens >= 2.0,
-    hmatrix >= 0.20,
     lens,
     matrix >= 0.3.6 && < 0.3.7,
-    mwc-probability,
-    mwc-random,
-    numhask >= 0.7 && < 0.8,
+    mwc-probability >= 2.3.1 && < 2.4,
+    numhask >= 0.7.1 && < 0.8,
     numhask-array >= 0.8 && < 0.9,
     primitive >= 0.7,
     profunctors >= 5.5,
@@ -45,10 +43,6 @@
   other-modules:
   default-language: Haskell2010
   default-extensions:
-    NoImplicitPrelude
-    NegativeLiterals
-    OverloadedStrings
-    UnicodeSyntax
   ghc-options:
     -Wall
     -Wcompat
@@ -70,10 +64,6 @@
     mealy
   default-language: Haskell2010
   default-extensions:
-    NoImplicitPrelude
-    NegativeLiterals
-    OverloadedStrings
-    UnicodeSyntax
   ghc-options:
     -Wall
     -Wcompat
diff --git a/src/Data/Mealy.hs b/src/Data/Mealy.hs
--- a/src/Data/Mealy.hs
+++ b/src/Data/Mealy.hs
@@ -60,10 +60,6 @@
     zeroModel1,
     depModel1,
 
-    -- * conversion
-    foldB,
-    maB,
-
     -- * median
     Medianer (..),
     onlineL1,
@@ -77,7 +73,6 @@
 import Data.Fold hiding (M)
 import Data.Functor.Rep
 import Data.Generics.Labels ()
--- import qualified NumHask.Array.HMatrix as HM
 
 -- import qualified Numeric.LinearAlgebra as LA
 
@@ -86,10 +81,6 @@
 import qualified NumHask.Array.Fixed as F
 import NumHask.Array.Shape (HasShape)
 import NumHask.Prelude hiding (L1, State, StateT, asum, fold, get, replace, runState, runStateT, state)
-import Numeric.Backprop (BVar, Reifies, W)
-import qualified Numeric.Backprop as B
-import qualified Prelude.Backprop as PB
-import qualified Prelude as P
 
 -- $setup
 -- Generate some random variates for the examples.
@@ -546,15 +537,6 @@
         * m
         + (m1 ^. #betaStd2X)
         * (s - 1)
-
-foldB :: (Reifies s W) => (BVar s Double -> BVar s Double) -> BVar s Double -> BVar s [Double] -> BVar s Double
-foldB f r xs = divide (PB.foldl' (step' f r) (B.T2 0 0) xs)
-  where
-    step' f' r' (B.T2 s c) a = uncurry B.T2 ((r P.*) $ s P.+ f' a, (r' P.*) $ c P.+ 1)
-    divide (B.T2 s c) = s P./ c
-
-maB :: Reifies s W => BVar s Double -> BVar s [Double] -> BVar s Double
-maB = foldB id
 
 -- | A rough Median.
 -- The average absolute value of the stat is used to callibrate estimate drift towards the median
diff --git a/src/Data/Mealy/Simulate.hs b/src/Data/Mealy/Simulate.hs
--- a/src/Data/Mealy/Simulate.hs
+++ b/src/Data/Mealy/Simulate.hs
@@ -15,8 +15,7 @@
 
 import Control.Monad.Primitive (PrimState)
 import NumHask.Prelude hiding (fold)
-import System.Random.MWC
-import System.Random.MWC.Probability hiding (beta)
+import System.Random.MWC.Probability
 
 -- $setup
 -- >>> :set -XFlexibleContexts