diff --git a/LICENSE b/LICENSE
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--- /dev/null
+++ b/LICENSE
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+Copyright Matt Noonan (c) 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 Matt Noonan 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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+# lawful: Assert that your typeclass instances are lawful
+
+## What is this package for?
+
+This small library provides a single two-parameter typeclass `Lawful c t`,
+where `c` is a typeclass and `t` is a type. Declaring an instance of
+`Lawful C T` is an assertion that "the instance for `C T` obeys the laws of
+the class `C` (whatever *that* means!)"
+
+For example, a lawful instance of `Eq T` should satisfy the reflexive
+law `x == x` for all `x :: T`.  This is certainly true for most types, such
+as `Int` or `[a]` when `Eq a` is lawful, so we can define
+
+```haskell
+Lawful Eq Int
+Lawful Eq a => Lawful Eq [a]
+```
+
+But it *isn't* true for `Double`:
+
+```
+λ> nan = 0 / 0 :: Double
+λ> nan == nan
+False
+
+```
+
+## Why is there a `c t` constraint on `Lawful c t`?
+
+This constraint lets you use a `Lawful c t` wherever a `c t` would be expected, 
+as in:
+
+```haskell
+same :: Lawful Eq a => a -> a -> Bool
+same x y = x == y
+```
+
+## How do I know what laws are expected from a typeclass?
+
+If everybody more-or-less agrees on what the right laws are, hopefully they bothered to
+write them down somewhere. If they didn't, then sorry! You're on your own!
+
+## Shouldn't all typeclass instances be lawful anyway, making this package useless?
+
+Wouldn't that be nice?
diff --git a/Setup.hs b/Setup.hs
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+++ b/Setup.hs
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+import Distribution.Simple
+main = defaultMain
diff --git a/lawful.cabal b/lawful.cabal
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+++ b/lawful.cabal
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+name:                lawful
+version:             0.1.0.0
+-- synopsis:
+-- description:
+homepage:            https://github.com/matt-noonan/lawful#readme
+license:             BSD3
+license-file:        LICENSE
+author:              Matt Noonan
+maintainer:          matt.noonan@gmail.com
+copyright:           (c) 2018 Matt Noonan
+category:            Safe
+synopsis:            Assert the lawfulness of your typeclass instances.
+description:         Assert the lawfulness of your typeclass instances.
+build-type:          Simple
+extra-source-files:  README.md
+cabal-version:       >=1.10
+
+library
+  hs-source-dirs:      src
+  exposed-modules:     Lawful
+  build-depends:       base >= 4.7 && < 5
+  default-language:    Haskell2010
+
+source-repository head
+  type:     git
+  location: https://github.com/matt-noonan/lawful
diff --git a/src/Lawful.hs b/src/Lawful.hs
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+{-# LANGUAGE MultiParamTypeClasses   #-}
+{-# LANGUAGE FlexibleContexts        #-}
+{-# LANGUAGE ConstraintKinds         #-}
+{-# LANGUAGE UndecidableSuperClasses #-}
+
+module Lawful (Lawful) where
+
+-- | A `Lawful c t` instance asserts that the typeclass `c t`
+--   obeys the expected laws of `c` (whatever that means).
+class c t => Lawful c t
+
+---------------------------------------------------------------------
+--  Some lawful instances of `Eq`, `Ord`
+
+-- Base types
+instance Lawful Eq  Bool
+instance Lawful Ord Bool
+
+instance Lawful Eq  Int
+instance Lawful Ord Int
+
+instance Lawful Eq  Integer
+instance Lawful Ord Integer
+
+-- Lists
+instance Lawful Eq  a => Lawful Eq [a]
+instance Lawful Ord a => Lawful Ord [a]
+
+-- Maybe
+instance Lawful Eq  a => Lawful Eq  (Maybe a)
+instance Lawful Ord a => Lawful Ord (Maybe a)
+
+-- Either
+instance (Lawful Eq  a, Lawful Eq  b) => Lawful Eq  (Either a b)
+instance (Lawful Ord a, Lawful Ord b) => Lawful Ord (Either a b)