diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,3 +1,8 @@
+## [0.6.2] - 2023-07-25
+- withAllConstraint, withSomeAllConstraint
+- listTypeToListM, listTypeForList, listTypeFind
+- fixedListLength, fixedListGenerate, Eq FixedList
+
 ## [0.6.1] - 2022-09-12
 - new ListLength type family and associated functions
 - new Greater type family and associated functions
diff --git a/src/Data/PeanoNat.hs b/src/Data/PeanoNat.hs
--- a/src/Data/PeanoNat.hs
+++ b/src/Data/PeanoNat.hs
@@ -2,7 +2,6 @@
 
 import GHC.TypeNats
 import Import
-import Numeric.Natural
 
 -- | Inductive natural numbers.
 data PeanoNat
diff --git a/src/Data/Type/Witness/General/AllConstraint.hs b/src/Data/Type/Witness/General/AllConstraint.hs
--- a/src/Data/Type/Witness/General/AllConstraint.hs
+++ b/src/Data/Type/Witness/General/AllConstraint.hs
@@ -6,6 +6,15 @@
 class AllConstraint c w where
     allConstraint :: forall t. Dict (c (w t))
 
+withAllConstraint ::
+       forall k (c :: Type -> Constraint) (w :: k -> Type) (a :: k) (r :: Type). AllConstraint c w
+    => w a
+    -> (c (w a) => r)
+    -> r
+withAllConstraint _ call =
+    case allConstraint @Type @k @c @w @a of
+        Dict -> call
+
 instance AllConstraint Show ((:~:) t) where
     allConstraint = Dict
 
diff --git a/src/Data/Type/Witness/Specific/FixedList.hs b/src/Data/Type/Witness/Specific/FixedList.hs
--- a/src/Data/Type/Witness/Specific/FixedList.hs
+++ b/src/Data/Type/Witness/Specific/FixedList.hs
@@ -35,6 +35,21 @@
     sequenceA NilFixedList = pure NilFixedList
     sequenceA (ConsFixedList fa l) = liftA2 ConsFixedList fa $ sequenceA l
 
+instance Eq a => Eq (FixedList n a) where
+    NilFixedList == NilFixedList = True
+    (ConsFixedList a la) == (ConsFixedList b lb) =
+        if a == b
+            then la == lb
+            else False
+
+fixedListLength :: FixedList n a -> PeanoNatType n
+fixedListLength NilFixedList = ZeroType
+fixedListLength (ConsFixedList _ l) = SuccType $ fixedListLength l
+
+fixedListGenerate :: Applicative m => PeanoNatType n -> m a -> m (FixedList n a)
+fixedListGenerate ZeroType _ = pure NilFixedList
+fixedListGenerate (SuccType n) ma = liftA2 ConsFixedList ma $ fixedListGenerate n ma
+
 fixedFromList :: [a] -> (forall n. PeanoNatType n -> FixedList n a -> r) -> r
 fixedFromList [] call = call ZeroType NilFixedList
 fixedFromList (a:aa) call = fixedFromList aa $ \n l -> call (SuccType n) $ ConsFixedList a l
diff --git a/src/Data/Type/Witness/Specific/List/List.hs b/src/Data/Type/Witness/Specific/List/List.hs
--- a/src/Data/Type/Witness/Specific/List/List.hs
+++ b/src/Data/Type/Witness/Specific/List/List.hs
@@ -78,10 +78,16 @@
 listTypeToList _wr NilListType = []
 listTypeToList wr (ConsListType wa rest) = (wr wa) : (listTypeToList wr rest)
 
-listTypeFor :: Applicative m => ListType w t -> (forall a. w a -> m r) -> m [r]
-listTypeFor NilListType _ = pure []
-listTypeFor (ConsListType t tt) f = liftA2 (:) (f t) $ listTypeFor tt f
+listTypeToListM :: Applicative m => (forall a. w a -> m r) -> ListType w t -> m [r]
+listTypeToListM _ NilListType = pure []
+listTypeToListM f (ConsListType t tt) = liftA2 (:) (f t) $ listTypeToListM f tt
 
+listTypeFor :: Applicative m => ListType w1 t -> (forall a. w1 a -> m (w2 a)) -> m (ListType w2 t)
+listTypeFor lt f = mapMListType f lt
+
+listTypeForList :: Applicative m => ListType w t -> (forall a. w a -> m r) -> m [r]
+listTypeForList lt f = listTypeToListM f lt
+
 listTypeFor_ :: Applicative m => ListType w t -> (forall a. w a -> m ()) -> m ()
 listTypeFor_ NilListType _ = pure ()
 listTypeFor_ (ConsListType t tt) f = f t *> listTypeFor_ tt f
@@ -98,3 +104,10 @@
 listTypeFromFixedList NilFixedList call = call NilListType
 listTypeFromFixedList (ConsFixedList (MkSome wa) l) call =
     listTypeFromFixedList l $ \rest -> call $ ConsListType wa rest
+
+listTypeFind :: (forall a. w a -> Maybe r) -> ListType w tt -> Maybe r
+listTypeFind _ NilListType = Nothing
+listTypeFind f (ConsListType a aa) =
+    case f a of
+        Just r -> Just r
+        Nothing -> listTypeFind f aa
diff --git a/src/Data/Type/Witness/Specific/Natural.hs b/src/Data/Type/Witness/Specific/Natural.hs
--- a/src/Data/Type/Witness/Specific/Natural.hs
+++ b/src/Data/Type/Witness/Specific/Natural.hs
@@ -27,7 +27,6 @@
 import Data.Type.Witness.Specific.PeanoNat
 import GHC.TypeNats
 import Import
-import Numeric.Natural
 import Unsafe.Coerce
 
 type NaturalType :: Nat -> Type
diff --git a/src/Data/Type/Witness/Specific/Some.hs b/src/Data/Type/Witness/Specific/Some.hs
--- a/src/Data/Type/Witness/Specific/Some.hs
+++ b/src/Data/Type/Witness/Specific/Some.hs
@@ -71,8 +71,15 @@
 instance forall k (w :: k -> Type). TestOrder w => Ord (Some w) where
     compare (MkSome wa) (MkSome wb) = wOrderingToOrdering $ testCompare wa wb
 
+withSomeAllConstraint ::
+       forall k (c :: Type -> Constraint) (w :: k -> Type) (r :: Type). AllConstraint c w
+    => Some w
+    -> (forall a. c (w a) => w a -> r)
+    -> r
+withSomeAllConstraint (MkSome wa) call = withAllConstraint @k @c wa $ call wa
+
 instance forall k (w :: k -> Type). AllConstraint Show w => Show (Some w) where
-    show (MkSome wa) = allShow wa
+    show swa = withSomeAllConstraint @k @Show swa show
 
 someForToSome :: SomeFor f w -> Some w
 someForToSome (MkSomeFor wa _) = MkSome wa
diff --git a/witness.cabal b/witness.cabal
--- a/witness.cabal
+++ b/witness.cabal
@@ -1,13 +1,11 @@
 cabal-version: 2.2
 
--- This file has been generated from package.yaml by hpack version 0.34.4.
+-- This file has been generated from package.yaml by hpack version 0.35.2.
 --
 -- see: https://github.com/sol/hpack
---
--- hash: aae0fd4e94350169efa7229b1559a55e3b9d2ed3d389f607534a15403307b6b1
 
 name:           witness
-version:        0.6.1
+version:        0.6.2
 synopsis:       values that witness types
 description:    A /witness/ is a value that witnesses some sort of constraint on some list of type variables. This library provides support for a wide variety of witness types. It also provides classes for /representatives/, which are values that represent types.
 category:       Data
@@ -23,6 +21,42 @@
     changelog.md
 
 library
+  exposed-modules:
+      Data.Type.Witness.Apply
+      Data.PeanoNat
+      Data.Type.Witness.General.TestHetEquality
+      Data.Type.Witness.General.HetConstraint
+      Data.Type.Witness.Specific.Some
+      Data.Type.Witness.Specific.All
+      Data.Type.Witness.General.AllConstraint
+      Data.Type.Witness.General.WitnessConstraint
+      Data.Type.Witness.General.WitnessValue
+      Data.Type.Witness.General.ListElement
+      Data.Type.Witness.Specific.Symbol
+      Data.Type.Witness.General.Finite
+      Data.Type.Witness.Specific.Single
+      Data.Type.Witness.Specific.Pair
+      Data.Type.Witness.Specific.Empty
+      Data.Type.Witness.Specific.Either
+      Data.Type.Witness.Specific.FiniteAllFor
+      Data.Type.Witness.Specific.WitnessMap.Of
+      Data.Type.Witness.Specific.WitnessMap.For
+      Data.Type.Witness.Specific.OrderedWitnessMap.Of
+      Data.Type.Witness.Specific.OrderedWitnessMap.For
+      Data.Type.Witness.Specific.PeanoNat
+      Data.Type.Witness.Specific.Natural
+      Data.Type.Witness.Specific.FixedList
+      Data.Type.Witness.Specific.List.Element
+      Data.Type.Witness.Specific.List.List
+      Data.Type.Witness.Specific.Concat
+      Data.Type.Witness.Specific.ApplyStack
+      Data.Type.Witness.Specific.List.Product
+      Data.Type.Witness.Specific.List.Sum
+      Data.Type.Witness.General.Representative
+      Data.Type.Witness.General.Order
+      Data.Type.Witness
+  other-modules:
+      Import
   hs-source-dirs:
       src
   default-extensions:
@@ -72,44 +106,8 @@
       ViewPatterns
   ghc-options: -Wall -Wincomplete-uni-patterns -Wincomplete-record-updates -Wcompat -Wnoncanonical-monad-instances
   build-depends:
-      base >=4.15 && <5
+      base >=4.16 && <5
     , constraints >=0.13
     , containers >=0.4
     , countable >=1.2
-  exposed-modules:
-      Data.Type.Witness.Apply
-      Data.PeanoNat
-      Data.Type.Witness.General.TestHetEquality
-      Data.Type.Witness.General.HetConstraint
-      Data.Type.Witness.Specific.Some
-      Data.Type.Witness.Specific.All
-      Data.Type.Witness.General.AllConstraint
-      Data.Type.Witness.General.WitnessConstraint
-      Data.Type.Witness.General.WitnessValue
-      Data.Type.Witness.General.ListElement
-      Data.Type.Witness.Specific.Symbol
-      Data.Type.Witness.General.Finite
-      Data.Type.Witness.Specific.Single
-      Data.Type.Witness.Specific.Pair
-      Data.Type.Witness.Specific.Empty
-      Data.Type.Witness.Specific.Either
-      Data.Type.Witness.Specific.FiniteAllFor
-      Data.Type.Witness.Specific.WitnessMap.Of
-      Data.Type.Witness.Specific.WitnessMap.For
-      Data.Type.Witness.Specific.OrderedWitnessMap.Of
-      Data.Type.Witness.Specific.OrderedWitnessMap.For
-      Data.Type.Witness.Specific.PeanoNat
-      Data.Type.Witness.Specific.Natural
-      Data.Type.Witness.Specific.FixedList
-      Data.Type.Witness.Specific.List.Element
-      Data.Type.Witness.Specific.List.List
-      Data.Type.Witness.Specific.Concat
-      Data.Type.Witness.Specific.ApplyStack
-      Data.Type.Witness.Specific.List.Product
-      Data.Type.Witness.Specific.List.Sum
-      Data.Type.Witness.General.Representative
-      Data.Type.Witness.General.Order
-      Data.Type.Witness
-  other-modules:
-      Import
   default-language: Haskell2010