diff --git a/Data/Either/Both.hs b/Data/Either/Both.hs
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+++ b/Data/Either/Both.hs
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+module Data.Either.Both where
+
+import Data.Bifoldable (Bifoldable (..))
+import Data.Bifunctor (Bifunctor (..))
+import Data.Bitraversable (Bitraversable (..))
+import Data.Functor.Classes
+
+data Either' a b = JustLeft a | JustRight b | Both a b
+  deriving (Read, Show)
+
+instance Bifunctor Either' where
+    bimap f g = \ case JustLeft a -> JustLeft (f a)
+                       JustRight b -> JustRight (g b)
+                       Both a b -> Both (f a) (g b)
+
+instance Bifoldable Either' where
+    bifoldMap f g = \ case JustLeft a -> f a
+                           JustRight b -> g b
+                           Both a b -> f a <> g b
+
+instance Bitraversable Either' where
+    bitraverse f g = \ case JustLeft a -> JustLeft <$> f a
+                            JustRight b -> JustRight <$> g b
+                            Both a b -> Both <$> f a <*> g b
+
+instance Eq2 Either' where
+    liftEq2 f g x y = case (toMaybes x, toMaybes y) of
+        ((am₁, bm₁), (am₂, bm₂)) -> liftEq f am₁ am₂ && liftEq g bm₁ bm₂
+
+instance Ord2 Either' where
+    liftCompare2 f g x y = case (toMaybes x, toMaybes y) of
+        ((am₁, bm₁), (am₂, bm₂)) -> liftCompare f am₁ am₂ <> liftCompare g bm₁ bm₂
+
+instance (Eq a, Eq b) => Eq (Either' a b) where (==) = eq2
+instance (Ord a, Ord b) => Ord (Either' a b) where compare = compare2
+
+instance (Semigroup a, Semigroup b) => Semigroup (Either' a b) where
+    JustLeft  a₁ <> JustLeft  a₂ = JustLeft  (a₁ <> a₂)
+    JustRight b₁ <> JustRight b₂ = JustRight (b₁ <> b₂)
+    JustLeft  a₁ <> JustRight b₁ = Both a₁ b₁
+    JustRight b₁ <> JustLeft  a₁ = Both a₁ b₁
+    JustLeft  a₁ <> Both a₂ b₂   = Both (a₁ <> a₂) b₂
+    JustRight b₁ <> Both a₂ b₂   = Both a₂ (b₁ <> b₂)
+    Both a₁ b₁   <> JustLeft  a₂ = Both (a₁ <> a₂) b₁
+    Both a₁ b₁   <> JustRight b₂ = Both a₁ (b₁ <> b₂)
+    Both a₁ b₁   <> Both a₂ b₂   = Both (a₁ <> a₂) (b₁ <> b₂)
+
+instance (Monoid a, Monoid b) => Monoid (Either' a b) where
+    mempty = Both mempty mempty
+
+fromMaybes :: Maybe a -> Maybe b -> Maybe (Either' a b)
+fromMaybes Nothing Nothing = Nothing
+fromMaybes (Just a) Nothing = Just (JustLeft a)
+fromMaybes Nothing (Just b) = Just (JustRight b)
+fromMaybes (Just a) (Just b) = Just (Both a b)
+
+toMaybes :: Either' a b -> (Maybe a, Maybe b)
+toMaybes (JustLeft a) = (Just a, Nothing)
+toMaybes (JustRight b) = (Nothing, Just b)
+toMaybes (Both a b) = (Just a, Just b)
diff --git a/LICENSE b/LICENSE
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--- /dev/null
+++ b/LICENSE
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+Copyright M Farkas-Dyck © 2018
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+
+    * Redistributions in binary form must reproduce the above
+      copyright notice, this list of conditions and the following
+      disclaimer in the documentation and/or other materials provided
+      with the distribution.
+
+    * Neither the name of M Farkas-Dyck nor the names of other
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/README.md b/README.md
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--- /dev/null
+++ b/README.md
@@ -0,0 +1,1 @@
+# either-prime
diff --git a/Setup.hs b/Setup.hs
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--- /dev/null
+++ b/Setup.hs
@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain
diff --git a/either-both.cabal b/either-both.cabal
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--- /dev/null
+++ b/either-both.cabal
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+name:                either-both
+version:             0.1.0.0
+synopsis:            Either or both
+-- description:
+license:             BSD3
+license-file:        LICENSE
+author:              M Farkas-Dyck
+maintainer:          strake888@gmail.com
+copyright:           2018 M Farkas-Dyck
+category:            Data
+build-type:          Simple
+extra-source-files:  README.md
+cabal-version:       >=1.10
+
+library
+  hs-source-dirs:      .
+  exposed-modules:     Data.Either.Both
+  build-depends:       base >= 4.7 && < 5
+  default-language:    Haskell2010
+  default-extensions:  UnicodeSyntax
+                     , LambdaCase
+                     , InstanceSigs
+                     , PartialTypeSignatures
+                     , PolyKinds
+                     , ConstraintKinds
+                     , FlexibleContexts
+                     , FlexibleInstances
+                     , StandaloneDeriving
+                     , DeriveFunctor
+                     , DeriveFoldable
+                     , DeriveTraversable
+                     , OverloadedStrings
+  ghc-options:         -Wall -Wcompat -Wredundant-constraints -Wno-name-shadowing
+                       -Wincomplete-record-updates -Wincomplete-uni-patterns
+
+source-repository head
+  type:     git
+  location: https://github.com/strake/either-both.hs