diff --git a/primus.cabal b/primus.cabal
--- a/primus.cabal
+++ b/primus.cabal
@@ -5,12 +5,12 @@
 -- see: https://github.com/sol/hpack
 
 name:           primus
-version:        0.1.0.0
-synopsis:       NonEmpty and positive functions
+version:        0.2.0.0
+synopsis:       nonempty and positive functions
 description:    A library containing positive-valued and nonempty functions . Please see the README on GitHub at <https://github.com/gbwey/primus#readme>
 category:       Data, General
 homepage:       https://github.com/gbwey/primus#readme
-bug-reports:    https://github.com/gbwey/primus.git/issues
+bug-reports:    https://github.com/gbwey/primus/issues
 author:         Grant Weyburne <gbwey9@gmail.com>
 maintainer:     Grant Weyburne <gbwey9@gmail.com>
 copyright:      2022 Grant Weyburne
@@ -20,7 +20,7 @@
 
 source-repository head
   type: git
-  location: https://github.com/gbwey/primus.git
+  location: https://github.com/gbwey/primus
 
 library
   exposed-modules:
@@ -29,7 +29,6 @@
       Primus.Bool
       Primus.Enum
       Primus.Error
-      Primus.Extra
       Primus.Fold
       Primus.Lens
       Primus.List
@@ -63,12 +62,12 @@
       TestAsMaybe
       TestBool
       TestEnum
-      TestExtra
       TestFold
       TestList
       TestLRHist
       TestNonEmpty
       TestNum1
+      TestTypeLevel
       TestZipNonEmpty
       Paths_primus
   hs-source-dirs:
diff --git a/src/Primus.hs b/src/Primus.hs
--- a/src/Primus.hs
+++ b/src/Primus.hs
@@ -9,7 +9,6 @@
   module Primus.AsMaybe,
   module Primus.Bool,
   module Primus.Enum,
-  module Primus.Extra,
   module Primus.Error,
   module Primus.Fold,
   module Primus.List,
@@ -24,7 +23,6 @@
 import Primus.Bool
 import Primus.Enum
 import Primus.Error
-import Primus.Extra
 import Primus.Fold
 import Primus.List
 import Primus.NonEmpty
diff --git a/src/Primus/AsMaybe.hs b/src/Primus/AsMaybe.hs
--- a/src/Primus/AsMaybe.hs
+++ b/src/Primus/AsMaybe.hs
@@ -46,7 +46,7 @@
 import qualified Data.Semigroup as SG
 import Data.These
 import Data.These.Combinators
-import Primus.Extra
+import Primus.Error ((.@))
 
 -- | converts to a 'Maybe' for failure types
 class AsMaybe x b | x -> b where
@@ -142,7 +142,6 @@
   go a = case toMaybe (f a) of
     Nothing -> []
     Just x -> x : go x
-
 
 {- | like 'Data.List.unfoldr' but terminate using 'AsMaybe'
 
diff --git a/src/Primus/Enum.hs b/src/Primus/Enum.hs
--- a/src/Primus/Enum.hs
+++ b/src/Primus/Enum.hs
@@ -4,6 +4,7 @@
 {-# LANGUAGE TupleSections #-}
 {-# LANGUAGE TypeApplications #-}
 {-# LANGUAGE ViewPatterns #-}
+
 {- |
 Module      : Primus.Enum
 Description : methods for safe enumeration and enumeration on containers
@@ -136,16 +137,16 @@
 -- | calculates the minimum and maximum range of enumerations that can be stored in a container of the given size
 capacity :: forall a t z. (Bounded a, Enum a, Foldable t) => t z -> Either String (Integer, Integer)
 capacity (length -> len) = do
-      let z@(mn, mx) = minMax @a
-      lhs <- case compare mn 0 of
-            LT -> Right (-(-mn + 1) ^ len + 1)
-            EQ -> Right 0
-            GT -> Left $ "capacity: unsupported mn > 0: " ++ show z
-      rhs <- case compare 0 mx of
-            LT -> Right ((mx + 1) ^ len - 1)
-            EQ -> Right 0
-            GT -> Left $ "capacity: unsupported mx < 0: " ++ show z
-      pure (lhs,rhs)
+  let z@(mn, mx) = minMax @a
+  lhs <- case compare mn 0 of
+    LT -> Right (-(-mn + 1) ^ len + 1)
+    EQ -> Right 0
+    GT -> Left $ "capacity: unsupported mn > 0: " ++ show z
+  rhs <- case compare 0 mx of
+    LT -> Right ((mx + 1) ^ len - 1)
+    EQ -> Right 0
+    GT -> Left $ "capacity: unsupported mx < 0: " ++ show z
+  pure (lhs, rhs)
 
 {- | convert toEnum of "a" into a list containing "a"s
    zero is the empty list: see 'toEnumList'
diff --git a/src/Primus/Error.hs b/src/Primus/Error.hs
--- a/src/Primus/Error.hs
+++ b/src/Primus/Error.hs
@@ -29,6 +29,8 @@
 
   -- * decorate an error
   lmsg,
+  -- * miscellaneous
+  (.@),
 ) where
 
 import Control.Arrow
@@ -103,3 +105,9 @@
   \case
     [] -> programmError $ "fromList1P:" ++ msg
     x : xs -> x :| xs
+
+-- | compose a two arg function followed by a one arg function
+(.@) :: (c -> d) -> (a -> b -> c) -> a -> b -> d
+(.@) = (.) . (.)
+
+infixr 8 .@
diff --git a/src/Primus/Extra.hs b/src/Primus/Extra.hs
deleted file mode 100644
--- a/src/Primus/Extra.hs
+++ /dev/null
@@ -1,53 +0,0 @@
-{-# LANGUAGE AllowAmbiguousTypes #-}
-{-# LANGUAGE PolyKinds #-}
-{-# LANGUAGE RankNTypes #-}
-{-# LANGUAGE ScopedTypeVariables #-}
-
-{- |
-Module      : Primus.Extra
-Description : miscellaneous functions
-Copyright   : (c) Grant Weyburne, 2022
-License     : BSD-3
--}
-module Primus.Extra (
-  on1,
-  on2,
-  comparing1,
-  (.@),
-) where
-
--- | more flexible version of 'Data.Function.on' that allows differing types for the same container
-on1 ::
-  forall f a a' b c.
-  (b -> b -> c) ->
-  (forall x. f x -> b) ->
-  f a ->
-  f a' ->
-  c
-on1 f g fa fa' = f (g fa) (g fa')
-
--- | more flexible version of 'Data.Function.on' that allows differing types for the same container but using two parameters
-on2 ::
-  forall f a a' a2 a2' b c.
-  (b -> b -> c) ->
-  (forall x y. f x y -> b) ->
-  f a a2 ->
-  f a' a2' ->
-  c
-on2 f g fa fa' = f (g fa) (g fa')
-
--- | more flexible version of 'compare' that allows differing types for the same container
-comparing1 ::
-  forall f a a' b.
-  Ord b =>
-  (forall x. f x -> b) ->
-  f a ->
-  f a' ->
-  Ordering
-comparing1 g fa fa' = compare (g fa) (g fa')
-
--- | compose a two arg function followed by a one arg function
-(.@) :: (c -> d) -> (a -> b -> c) -> a -> b -> d
-(.@) = (.) . (.)
-
-infixr 8 .@
diff --git a/src/Primus/Fold.hs b/src/Primus/Fold.hs
--- a/src/Primus/Fold.hs
+++ b/src/Primus/Fold.hs
@@ -82,7 +82,6 @@
 import Data.These
 import Data.These.Combinators
 import Primus.Error
-import Primus.Extra
 
 data Hist a b = Hist ![a] ![a] !b
 
@@ -449,7 +448,7 @@
 
 -- | 'Data.List.reverse' for a traversable container
 reverseT :: forall a t. Traversable t => t a -> t a
-reverseT = frp . wrapL reverse
+reverseT = frp . wrapL reverseF
 
 -- | 'Data.List.sortBy' for a traversable container
 sortByT :: forall a t. Traversable t => (a -> a -> Ordering) -> t a -> t a
diff --git a/src/Primus/LRHist.hs b/src/Primus/LRHist.hs
--- a/src/Primus/LRHist.hs
+++ b/src/Primus/LRHist.hs
@@ -1,8 +1,8 @@
 {-# LANGUAGE DataKinds #-}
 {-# LANGUAGE DeriveTraversable #-}
 {-# LANGUAGE DerivingStrategies #-}
-{-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE GADTs #-}
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
diff --git a/src/Primus/Lens.hs b/src/Primus/Lens.hs
--- a/src/Primus/Lens.hs
+++ b/src/Primus/Lens.hs
@@ -4,7 +4,6 @@
 {- |
 Module      : Primus.Lens
 Description : minimal lens interfaces
-
 -}
 module Primus.Lens (
   Lens,
diff --git a/src/Primus/List.hs b/src/Primus/List.hs
--- a/src/Primus/List.hs
+++ b/src/Primus/List.hs
@@ -60,7 +60,6 @@
 import GHC.Stack
 import Primus.Bool
 import Primus.Error
-import Primus.Extra
 
 -- | split a list into overlapping pairs plus overflow
 pairsOf1 :: [a] -> ([(a, a)], Maybe a)
diff --git a/src/Primus/NonEmpty.hs b/src/Primus/NonEmpty.hs
--- a/src/Primus/NonEmpty.hs
+++ b/src/Primus/NonEmpty.hs
@@ -111,7 +111,6 @@
 import qualified GHC.Exts as GE (IsList (..))
 import Primus.Bool
 import Primus.Error
-import Primus.Extra
 import Primus.Fold
 import Primus.Lens
 
@@ -529,4 +528,3 @@
 sumP :: Foldable1 t => t Pos -> Pos
 sumP = L.foldr1 (+!)
 {-# INLINE sumP #-}
-
diff --git a/src/Primus/Num1.hs b/src/Primus/Num1.hs
--- a/src/Primus/Num1.hs
+++ b/src/Primus/Num1.hs
@@ -26,7 +26,6 @@
 import GHC.Natural
 import Primus.Enum
 import Primus.Error
-import Primus.Extra
 
 -- | run a function of one integer against the underlying 'Num1' type
 withOp :: Num1 a => (Integer -> Integer) -> a -> Either String a
diff --git a/src/Primus/Rep.hs b/src/Primus/Rep.hs
--- a/src/Primus/Rep.hs
+++ b/src/Primus/Rep.hs
@@ -30,7 +30,6 @@
 import qualified Data.List.NonEmpty as N
 import Primus.Enum
 import Primus.Error
-import Primus.Extra
 import Primus.Fold
 
 -- | builds a representable from the left using past and future inputs
diff --git a/src/Primus/TypeLevel.hs b/src/Primus/TypeLevel.hs
--- a/src/Primus/TypeLevel.hs
+++ b/src/Primus/TypeLevel.hs
@@ -21,22 +21,15 @@
   Snd,
   Fsts,
   Snds,
-  Length,
-  Len1T,
+  LengthT,
   NotEqTC,
   Cons1T,
-  Snoc1T,
-  Snoc1LT,
   SnocT,
   InitT,
-  Init1T,
-  Last1T,
-  Head1T,
-  App1T,
+  LastT,
   ApplyConstraints1,
   ApplyConstraint,
   ApplyConstraints,
-  UnconsT,
   UnsnocT,
   FirstConsT,
   ToITupleT,
@@ -96,19 +89,14 @@
   Snds ('(_, b) ': rs) = b ': Snds rs
 
 -- | 'length' at the typelevel
-type Length :: forall k. [k] -> Nat
-type family Length rs where
-  Length '[] = 0
-  Length (_ ': '[]) = 1
-  Length (_ ': _ ': '[]) = 2
-  Length (_ ': _ ': _ ': '[]) = 3
-  Length (_ ': _ ': _ ': _ ': '[]) = 4
-  Length (_ ': _ ': _ ': _ ': _ ': rs) = 5 + Length rs
-
--- | get the length of a type level nonempty list
-type Len1T :: forall k. NonEmpty k -> k
-type family Len1T ns where
-  Len1T (_ ':| ns) = 1 GN.+ Length ns
+type LengthT :: forall k. [k] -> Nat
+type family LengthT rs where
+  LengthT '[] = 0
+  LengthT '[_] = 1
+  LengthT '[_, _] = 2
+  LengthT '[_, _, _] = 3
+  LengthT '[_, _, _, _] = 4
+  LengthT (_ ': _ ': _ ': _ ': _ ': rs) = 5 + LengthT rs
 
 -- | ensure that two types are not equal
 type NotEqTC :: forall k k1. k -> k1 -> Constraint
@@ -123,29 +111,12 @@
 type family Cons1T a ys = result | result -> a ys where
   Cons1T a (b ':| bs) = a ':| b ': bs
 
--- | snoc a nonempty list type to a type
-type Snoc1T :: forall k. NonEmpty k -> k -> NonEmpty k
-type family Snoc1T as b where
-  Snoc1T (a ':| as) b = a ':| SnocT as b
-
 -- | snoc a type list to a type
 type SnocT :: forall k. [k] -> k -> [k]
 type family SnocT as b where
   SnocT '[] b = '[b]
   SnocT (a ': as) b = a ': SnocT as b
 
--- | snoc a type list to a type
-type Snoc1LT :: forall k. [k] -> k -> NonEmpty k
-type family Snoc1LT as b where
-  Snoc1LT '[] b = b ':| '[]
-  Snoc1LT (a ': as) b = Cons1T a (Snoc1LT as b)
-
--- | append two nonempty lists at the type level
-type App1T :: forall k. NonEmpty k -> NonEmpty k -> NonEmpty k
-type family App1T x y where
-  App1T (a ':| '[]) y = Cons1T a y
-  App1T (a ':| a1 ': as) y = Cons1T a (App1T (a1 ':| as) y)
-
 -- | create a constraint from a type and list of constraints taking a type
 type ApplyConstraints1 :: forall k. [k -> Constraint] -> k -> Constraint
 type family ApplyConstraints1 xs x where
@@ -164,16 +135,12 @@
   ApplyConstraints '[] _ = ()
   ApplyConstraints (c ': cs) xs = (ApplyConstraint c xs, ApplyConstraints cs xs)
 
--- | uncons a type level nonempty list
-type UnconsT :: forall k. NonEmpty k -> (k, [k])
-type family UnconsT ns = result | result -> ns where
-  UnconsT (a ':| as) = '(a, as)
-
 -- | unsnoc a type level nonempty list
-type UnsnocT :: forall k. NonEmpty k -> ([k], k)
+type UnsnocT :: forall k. [k] -> ([k], k)
 type family UnsnocT ns where
-  UnsnocT (a ':| '[]) = '( '[], a)
-  UnsnocT (a ':| a1 ': as) = FirstConsT a (UnsnocT (a1 ':| as))
+  UnsnocT '[] = GL.TypeError ('GL.Text "UnsnocT: undefined for empty indices")
+  UnsnocT '[a] = '( '[], a)
+  UnsnocT (a ': a1 ': as) = FirstConsT a (UnsnocT (a1 ': as))
 
 -- | cons a type to the first element in a tuple
 type FirstConsT :: forall k k1. k -> ([k], k1) -> ([k], k1)
@@ -258,22 +225,12 @@
 -- | get the init of a list
 type InitT :: forall a. [a] -> [a]
 type family InitT xs where
-  InitT '[] = GL.TypeError ( 'GL.Text "InitT: undefined for 1d")
-  InitT (_ ': '[]) = '[]
+  InitT '[] = GL.TypeError ( 'GL.Text "InitT: undefined for empty indices")
+  InitT '[_] = '[]
   InitT (n ': m ': ns) = n ': InitT (m ': ns)
 
--- | get the init of a nonempty list
-type Init1T :: forall a. NonEmpty a -> NonEmpty a
-type family Init1T ns where
-  Init1T (n ':| ns) = n ':| InitT ns
-
 -- | peel off the bottom-most index in the matrix
-type Last1T :: forall k. NonEmpty k -> k
-type family Last1T ns where
-  Last1T (a ':| '[]) = a
-  Last1T (_ ':| (a1 : as)) = Last1T (a1 ':| as)
-
--- | get the head of a nonempty list
-type Head1T :: forall k. NonEmpty k -> k
-type family Head1T ns where
-  Head1T (a ':| _) = a
+type LastT :: forall k. [k] -> k
+type family LastT ns where
+  LastT '[a] = a
+  LastT (_ ': a1 : as) = LastT (a1 ': as)
diff --git a/src/Primus/ZipNonEmpty.hs b/src/Primus/ZipNonEmpty.hs
--- a/src/Primus/ZipNonEmpty.hs
+++ b/src/Primus/ZipNonEmpty.hs
@@ -72,4 +72,3 @@
 -- | iso for the zipnonempty constructor
 _Zip1 :: Iso (ZipNonEmpty a) (ZipNonEmpty b) (NonEmpty a) (NonEmpty b)
 _Zip1 = iso coerce coerce
-
diff --git a/test/Main.hs b/test/Main.hs
--- a/test/Main.hs
+++ b/test/Main.hs
@@ -5,13 +5,13 @@
 import qualified TestAsMaybe
 import qualified TestBool
 import qualified TestEnum
-import qualified TestExtra
 import qualified TestFold
 import qualified TestLRHist
 import qualified TestList
 import qualified TestNonEmpty
 import qualified TestNum1
 import qualified TestZipNonEmpty
+import qualified TestTypeLevel
 
 main :: IO ()
 main = do
@@ -29,13 +29,13 @@
         ( [ TestAsMaybe.suite
           , TestBool.suite
           , TestEnum.suite
-          , TestExtra.suite
           , TestFold.suite
           , TestList.suite
           , TestLRHist.suite
           , TestNonEmpty.suite
           , TestNum1.suite
---          , TestZipNonEmpty.suite
+          , TestTypeLevel.suite
+          --          , TestZipNonEmpty.suite
           ]
             ++ zs
         )
diff --git a/test/TestExtra.hs b/test/TestExtra.hs
deleted file mode 100644
--- a/test/TestExtra.hs
+++ /dev/null
@@ -1,17 +0,0 @@
-{-# LANGUAGE DataKinds #-}
-{-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE RankNTypes #-}
-{-# LANGUAGE ScopedTypeVariables #-}
-
-module TestExtra where
-
-import Primus.Extra
-import Test.Tasty
-import Test.Tasty.HUnit
-
-suite :: TestTree
-suite =
-  testGroup
-    "TestExtra"
-    [ testCase "on1" $ on1 compare length "adsf" [1 :: Int .. 2] @?= GT
-    ]
diff --git a/test/TestLRHist.hs b/test/TestLRHist.hs
--- a/test/TestLRHist.hs
+++ b/test/TestLRHist.hs
@@ -124,21 +124,21 @@
         map lhToEither zz2
           @?= [ Left "ab"
               , Right (This 'H')
-              , Left "dude"
+              , Left "oops"
               , Right (That 50)
               ]
     , testCase "lhToEitherI" $
         map lhToEitherI zz2
           @?= [ Left "ab"
               , Right (This 'H', (72, (2, ('y', (True, ())))))
-              , Left "dude"
+              , Left "oops"
               , Right (That 50, (50, (299, ('a', (False, ())))))
               ]
     , testCase "lhToEitherTuples" $
         map lhToEitherTuples zz2
           @?= [ Left "ab"
               , Right (This 'H', 72, 2, 'y', True)
-              , Left "dude"
+              , Left "oops"
               , Right (That 50, 50, 299, 'a', False)
               ]
     , testCase "lhToEitherTuples appLR" $
@@ -347,7 +347,7 @@
               if a > 50
                 then Right (This (chr a))
                 else Right (That a)
-            else Left "dude"
+            else Left "oops"
       )
 
 suiteCheckers :: TestTree
@@ -367,5 +367,3 @@
     . adjustOption (max $ TQ.QuickCheckTests n)
     . adjustOption (max $ TQ.QuickCheckMaxRatio ratio)
     . adjustOption (const (TQ.QuickCheckVerbose v))
-
-
diff --git a/test/TestNonEmpty.hs b/test/TestNonEmpty.hs
--- a/test/TestNonEmpty.hs
+++ b/test/TestNonEmpty.hs
@@ -10,8 +10,8 @@
 import Data.Char
 import Data.List.NonEmpty (NonEmpty (..))
 import qualified Data.List.NonEmpty as N
-import Data.These
 import Data.Pos
+import Data.These
 import Primus.Bool
 import Primus.Enum
 import Primus.NonEmpty
diff --git a/test/TestTypeLevel.hs b/test/TestTypeLevel.hs
new file mode 100644
--- /dev/null
+++ b/test/TestTypeLevel.hs
@@ -0,0 +1,42 @@
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RankNTypes #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE TypeApplications #-}
+
+module TestTypeLevel where
+
+import Primus.TypeLevel
+import Data.List.NonEmpty (NonEmpty(..))
+import Test.Tasty
+import Data.Pos
+import Test.Tasty.HUnit
+
+doit :: IO ()
+doit = defaultMain suite
+
+suite :: TestTree
+suite =
+  testGroup
+    "TestTypeLevel"
+    [ testCase "LengthT" $
+        pnat @(LengthT '[]) @?= 0
+    , testCase "LengthT" $
+        pnat @(LengthT '[ 1,2,3]) @?= 3
+    , testCase "LengthT" $
+        pnat @(LengthT '[ 1,2,3,4,5,6,7,8,9,10]) @?= 10
+    , testCase "LengthT" $
+        pnat @(LengthT '[ 1,2,3,4,5,6,7,8,9,10,11]) @?= 11
+    , testCase "LengthT" $
+        pnat @(LengthT '[ 1,2,3,4,5,6,7,8,9]) @?= 9
+    , testCase "LastT" $
+        pnat @(LastT '[ 1,2,3]) @?= 3
+    , testCase "InitT" $
+        fromNSP @(InitT '[ 1,2,3]) @?= _1P :| [_2P]
+    , testCase "SnocT" $
+        fromNSP @(SnocT '[ 1,2,3] 5) @?= _1P :| [_2P,_3P,_5P]
+    , testCase "UnsnocT Fst" $
+        fromNSP @(Fst (UnsnocT '[ 1,2,3,4])) @?= _1P :| [_2P,_3P]
+    , testCase "UnsnocT Snd" $
+        fromNP @(Snd (UnsnocT '[ 1,2,3,4])) @?= _4P
+    ]
diff --git a/test/TestZipNonEmpty.hs b/test/TestZipNonEmpty.hs
--- a/test/TestZipNonEmpty.hs
+++ b/test/TestZipNonEmpty.hs
@@ -10,11 +10,11 @@
 import Data.Foldable
 import qualified Data.List.NonEmpty as N
 import qualified Data.Monoid as MM
+import Primus.ZipNonEmpty
 import Test.QuickCheck
 import Test.QuickCheck.Checkers
 import "checkers" Test.QuickCheck.Classes
 import Test.Tasty
-import Primus.ZipNonEmpty
 import qualified Test.Tasty.QuickCheck as TQ
 
 argsVerbose :: Args
@@ -36,6 +36,7 @@
 testLawsZipNonEmptyIO :: IO ()
 testLawsZipNonEmptyIO = do
   traverse_ verboseBatch testLawsZipNonEmpty
+
 {-
 doit :: IO ()
 doit = defaultMain suite