diff --git a/README.md b/README.md
index b5d4a03..bdc771d 100644
--- a/README.md
+++ b/README.md
@@ -5,11 +5,9 @@ A (very WIP) lambda expression evaluator and debugger.
 I'd like to build the following:
 
 - [X] parsing with parsec
+  - need to harden tests a bit more but existing tests pass
 - [X] alpha/beta reduction to beta normal
 - [ ] substitutions for known abstractions (numbers can be written and are displayed as numbers rather than lambda terms)
-  - [ ] replace known terms in input
-  - [X] replace known terms in output
-  - [ ] support detection and replacement for generic church numerals (not just 1 and 0 (false))
 - [ ] persisted variables
 - [ ] display all steps in alpha/beta reductions until beta normal form is reached
 - [ ] online web-based lambda playground
diff --git a/lamb.cabal b/lamb.cabal
index 0a65674..88ff50e 100644
--- a/lamb.cabal
+++ b/lamb.cabal
@@ -14,9 +14,8 @@ executable lamb
     main-is:          Main.hs
     other-modules:    Parser,
                       Evaluation,
-                      Bruijn,
-                      Niceties
-    build-depends:    base, bimap, containers, parsec
+                      Bruijn
+    build-depends:    base, containers, parsec
     hs-source-dirs:   src
     default-language: Haskell2010
 
@@ -28,10 +27,7 @@ test-suite lamb-tests
                         ParserSpec,
                         Evaluation,
                         EvaluationSpec,
-                        Bruijn,
-                        BruijnSpec,
-                        Niceties,
-                        NicetiesSpec
-    build-depends:      base, bimap, containers, hspec, parsec
+                        BruijnSpec
+    build-depends:      base, containers, hspec, parsec
     build-tool-depends: hspec-discover:hspec-discover
     default-language:   Haskell2010
diff --git a/src/Main.hs b/src/Main.hs
index bd04634..6490c7c 100644
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -1,7 +1,6 @@
 module Main where
 
 import Evaluation (run)
-import Niceties (replaceKnowns)
 import Parser (parse)
 import System.Environment (getArgs)
 import System.IO (IOMode (ReadMode), hGetContents, openFile)
@@ -16,5 +15,5 @@ main = do
   case command of
     "run" -> do
       content <- openFile path ReadMode >>= hGetContents
-      either putStrLn putStrLn $ show . replaceKnowns . run <$> parse content
+      either putStrLn putStrLn $ show . run <$> parse content
     _ -> putStrLn $ "Unrecognized command: " ++ command
diff --git a/src/Niceties.hs b/src/Niceties.hs
deleted file mode 100644
index b2d9233..0000000
--- a/src/Niceties.hs
+++ /dev/null
@@ -1,245 +0,0 @@
-module Niceties where
-
-import Bruijn (toDeBruijn)
-import Data.Bimap (Bimap, fromList, lookupR)
-import Parser (Expr (Abstraction, Application, Variable))
-
-findKnown :: Expr -> Maybe String
-findKnown e = lookupR (toDeBruijn e) knownValues
-
--- | Replace known values in expression with proper names
-replaceKnowns :: Expr -> Expr
-replaceKnowns a@(Abstraction name body) = case findKnown a of
-  Just name' -> Variable name'
-  Nothing -> Abstraction name $ replaceKnowns body
-replaceKnowns (Application f arg) = Application (replaceKnowns f) (replaceKnowns arg)
-replaceKnowns v = v
-
-knownValues :: Bimap String Expr
-knownValues =
-  Data.Bimap.fromList
-    [ ( "I",
-        toDeBruijn $ Abstraction "x" (Variable "x")
-      ),
-      ( "true",
-        -- same as K
-        toDeBruijn $
-          Abstraction "x" (Abstraction "y" (Variable "x"))
-      ),
-      ( "false",
-        -- same as K*, `0`, `nil`
-        toDeBruijn $
-          Abstraction "x" (Abstraction "y" (Variable "y"))
-      ),
-      ( "S",
-        toDeBruijn $
-          Abstraction "x" $
-            Abstraction "y" $
-              Abstraction "z" $
-                Application
-                  (Application (Variable "x") (Variable "z"))
-                  (Application (Variable "y") (Variable "z"))
-      ),
-      ( "B",
-        toDeBruijn $
-          Abstraction "x" $
-            Abstraction "y" $
-              Abstraction "z" $
-                Application
-                  (Variable "x")
-                  (Application (Variable "y") (Variable "z"))
-      ),
-      ( "C",
-        toDeBruijn $
-          Abstraction "x" $
-            Abstraction "y" $
-              Abstraction "z" $
-                Application
-                  (Application (Variable "x") (Variable "z"))
-                  (Variable "y")
-      ),
-      ( "W",
-        toDeBruijn $
-          Abstraction "x" $
-            Abstraction "y" $
-              Application
-                (Application (Variable "x") (Variable "y"))
-                (Variable "y")
-      ),
-      ( "ω",
-        toDeBruijn $
-          Abstraction "x" $
-            Application (Variable "x") (Variable "x")
-      ),
-      -- Fixed points
-      ( "Y",
-        toDeBruijn $
-          Abstraction "f" $
-            Application
-              ( Abstraction "x" $
-                  Application
-                    (Variable "f")
-                    (Application (Variable "x") (Variable "x"))
-              )
-              ( Abstraction "x" $
-                  Application
-                    (Variable "f")
-                    (Application (Variable "x") (Variable "x"))
-              )
-      ),
-      ( "Z",
-        toDeBruijn $
-          Abstraction "f" $
-            Application
-              ( Abstraction "x" $
-                  Application (Variable "f") $
-                    Abstraction "v" $
-                      Application
-                        (Application (Variable "x") (Variable "x"))
-                        (Variable "v")
-              )
-              ( Abstraction "x" $
-                  Application (Variable "f") $
-                    Abstraction "v" $
-                      Application
-                        (Application (Variable "x") (Variable "x"))
-                        (Variable "v")
-              )
-      ),
-      -- Church numerals
-      -- Note: if you use the Church numeral recognition algorithm,
-      -- you may not need these in the Bimap at all.
-      ( "succ",
-        toDeBruijn $
-          Abstraction "n" $
-            Abstraction "f" $
-              Abstraction "x" $
-                Application
-                  (Variable "f")
-                  ( Application
-                      (Application (Variable "n") (Variable "f"))
-                      (Variable "x")
-                  )
-      ),
-      ( "plus",
-        toDeBruijn $
-          Abstraction "m" $
-            Abstraction "n" $
-              Abstraction "f" $
-                Abstraction "x" $
-                  Application
-                    (Application (Variable "m") (Variable "f"))
-                    ( Application
-                        (Application (Variable "n") (Variable "f"))
-                        (Variable "x")
-                    )
-      ),
-      ( "mult",
-        toDeBruijn $
-          Abstraction "m" $
-            Abstraction "n" $
-              Abstraction "f" $
-                Application
-                  (Variable "m")
-                  (Application (Variable "n") (Variable "f"))
-      ),
-      ( "exp",
-        toDeBruijn $
-          Abstraction "m" $
-            Abstraction "n" $
-              Application (Variable "n") (Variable "m")
-      ),
-      ( "pred",
-        toDeBruijn $
-          Abstraction "n" $
-            Abstraction "f" $
-              Abstraction "x" $
-                Application
-                  ( Application
-                      ( Application (Variable "n") $
-                          Abstraction "g" $
-                            Abstraction "h" $
-                              Application
-                                (Variable "h")
-                                (Application (Variable "g") (Variable "f"))
-                      )
-                      (Abstraction "u" (Variable "x"))
-                  )
-                  (Abstraction "u" (Variable "u"))
-      ),
-      ( "isZero",
-        toDeBruijn $
-          Abstraction "n" $
-            Application
-              ( Application (Variable "n") $
-                  Abstraction "x" $
-                    Abstraction "a" $
-                      Abstraction "b" (Variable "b")
-              )
-              (Abstraction "a" $ Abstraction "b" (Variable "a"))
-      ),
-      -- Church booleans
-      ( "and",
-        toDeBruijn $
-          Abstraction "p" $
-            Abstraction "q" $
-              Application
-                (Application (Variable "p") (Variable "q"))
-                (Variable "p")
-      ),
-      ( "or",
-        toDeBruijn $
-          Abstraction "p" $
-            Abstraction "q" $
-              Application
-                (Application (Variable "p") (Variable "p"))
-                (Variable "q")
-      ),
-      ( "not",
-        toDeBruijn $
-          Abstraction "p" $
-            Abstraction "a" $
-              Abstraction "b" $
-                Application
-                  (Application (Variable "p") (Variable "b"))
-                  (Variable "a")
-      ),
-      -- Pairs
-      ( "pair",
-        toDeBruijn $
-          Abstraction "x" $
-            Abstraction "y" $
-              Abstraction "f" $
-                Application
-                  (Application (Variable "f") (Variable "x"))
-                  (Variable "y")
-      ),
-      ( "fst",
-        toDeBruijn $
-          Abstraction "p" $
-            Application (Variable "p") $
-              Abstraction "x" $
-                Abstraction "y" (Variable "x")
-      ),
-      ( "snd",
-        toDeBruijn $
-          Abstraction "p" $
-            Application (Variable "p") $
-              Abstraction "x" $
-                Abstraction "y" (Variable "y")
-      ),
-      -- Lists
-      ( "cons",
-        toDeBruijn $
-          Abstraction "h" $
-            Abstraction "t" $
-              Abstraction "f" $
-                Abstraction "x" $
-                  Application
-                    (Application (Variable "f") (Variable "h"))
-                    ( Application
-                        (Application (Variable "t") (Variable "f"))
-                        (Variable "x")
-                    )
-      )
-    ]
diff --git a/src/Parser.hs b/src/Parser.hs
index 3cd4d7c..de8028c 100644
--- a/src/Parser.hs
+++ b/src/Parser.hs
@@ -6,7 +6,7 @@ import Text.Parsec
 import Text.Parsec.String (Parser)
 
 data Expr = Variable String | Abstraction String Expr | Application Expr Expr
-  deriving (Eq, Ord)
+  deriving (Eq)
 
 instance Show Expr where
   show (Variable name) = name
diff --git a/test.lm b/test.lm
index 1496ac5..3be6e04 100644
--- a/test.lm
+++ b/test.lm
@@ -1 +1 @@
-(λn. n (λx. λa. λb. b) (λa. λb. a)) (λf. λx. x)
+(λx.λy.λz. x z (y z)) (λa.λb. a) (λa.λb. a)
diff --git a/test/NicetiesSpec.hs b/test/NicetiesSpec.hs
deleted file mode 100644
index 59ad76f..0000000
--- a/test/NicetiesSpec.hs
+++ /dev/null
@@ -1,19 +0,0 @@
-module NicetiesSpec (spec) where
-
-import Bruijn (toDeBruijn)
-import Niceties (findKnown, replaceKnowns)
-import Parser (Expr (Abstraction, Application, Variable))
-import Test.Hspec
-
-spec :: Spec
-spec = do
-  describe "can find knowns" $ do
-    it "can find identity" $
-      findKnown identity `shouldBe` Just "I"
-  describe "replaceKnowns" $ do
-    it "can replace identity" $
-      replaceKnowns identity `shouldBe` Variable "I"
-    it "can replace identity of identity" $
-      replaceKnowns (Application identity identity) `shouldBe` Application (Variable "I") (Variable "I")
-  where
-    identity = toDeBruijn $ Abstraction "x" (Variable "x")