diff --git a/propa-tools.cabal b/propa-tools.cabal
index 51d278b..4d4c553 100644
--- a/propa-tools.cabal
+++ b/propa-tools.cabal
@@ -22,6 +22,7 @@ library
   exposed-modules:
       Propa.Lambda.Display
       Propa.Lambda.Term
+      Propa.Prolog.Example
       Propa.Prolog.Types
       Propa.Prolog.Unify
   other-modules:
diff --git a/src/Propa/Prolog/Example.hs b/src/Propa/Prolog/Example.hs
new file mode 100644
index 0000000..91ded59
--- /dev/null
+++ b/src/Propa/Prolog/Example.hs
@@ -0,0 +1,19 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Propa.Prolog.Example where
+
+import qualified Data.Text          as T
+
+import           Propa.Prolog.Types
+
+db :: Db T.Text
+db =
+  [ Def "append" [Stat "nil" [], Var "Y", Var "Y"] []
+  , Def "append" [Stat "cons" [Var "X", Var "XS"], Var "Y", Stat "cons" [Var "X", Var "Z"]] [Stat "append" [Var "XS", Var "Y", Var "Z"]]
+  ]
+
+l12 :: Term T.Text
+l12 = Stat "cons" [Stat "1" [], Stat "cons" [Stat "2" [], Stat "nil" []]]
+
+l345 :: Term T.Text
+l345 = Stat "cons" [Stat "3" [], Stat "cons" [Stat "4" [], Stat "cons" [Stat "5" [], Stat "nil" []]]]