diff --git a/casadi-bindings.cabal b/casadi-bindings.cabal
--- a/casadi-bindings.cabal
+++ b/casadi-bindings.cabal
@@ -1,5 +1,5 @@
 name:                casadi-bindings
-version:             2.4.1.5
+version:             2.4.1.6
 synopsis:            mid-level bindings to CasADi
 category:            Numerical, Math
 description:
@@ -74,3 +74,13 @@
 source-repository head
   type: git
   location: git://github.com/ghorn/casadi-bindings.git
+
+test-suite doctests
+  type:                exitcode-stdio-1.0
+  main-is:             doctests.hs
+  build-depends:       base >= 4 && < 5,
+                       doctest >= 0.8
+  default-language:    Haskell2010
+  ghc-options:         -threaded
+  hs-source-dirs:      tests
+
diff --git a/src/Casadi/Overloading.hs b/src/Casadi/Overloading.hs
--- a/src/Casadi/Overloading.hs
+++ b/src/Casadi/Overloading.hs
@@ -1,10 +1,12 @@
 {-# OPTIONS_GHC -Wall #-}
 
 module Casadi.Overloading
-       ( Fmod(..)
-       , ArcTan2(..)
-       , SymOrd(..)
+       ( ArcTan2(..)
        , Erf(..)
+       , Fmod(..)
+       , SymOrd(..)
+       , lt, gt
+       , ifLeqThen, ifGeqThen, ifEqThen, ifLtThen, ifGtThen
        ) where
 
 import Data.Fixed ( mod' )
@@ -23,10 +25,48 @@
 instance ArcTan2 Double where arctan2 = atan2
 instance ArcTan2 Float where arctan2 = atan2
 
--- | Ord, but returns a 1 or a 0 instead of True or False
-class SymOrd a where
+-- | error function
+class Erf a where
+  erf :: a -> a
+  erfinv :: a -> a
+
+
+-- | Ord, but returns a 1 or a 0 instead of True or False.
+-- If you optimize functions which include these, you are responsible for
+-- keeping things smooth enough.
+--
+-- >>> 41 `leq` 42 :: Double
+-- 1.0
+--
+-- >>> 42 `leq` 42 :: Double
+-- 1.0
+--
+-- >>> 43 `leq` 42 :: Double
+-- 0.0
+--
+-- >>> 41 `geq` 42 :: Double
+-- 0.0
+--
+-- >>> 42 `geq` 42 :: Double
+-- 1.0
+--
+-- >>> 43 `geq` 42 :: Double
+-- 1.0
+--
+-- >>> 41 `eq` 42 :: Double
+-- 0.0
+--
+-- >>> 42 `eq` 42 :: Double
+-- 1.0
+--
+-- >>> 43 `eq` 42 :: Double
+-- 0.0
+class Num a => SymOrd a where
+  -- | @<=@
   leq :: a -> a -> a
+  -- | @>=@
   geq :: a -> a -> a
+  -- | @==@
   eq :: a -> a -> a
 
 instance SymOrd Double where
@@ -38,7 +78,101 @@
   x `geq` y = if x >= y then 1 else 0
   x  `eq` y = if x == y then 1 else 0
 
--- | error function
-class Erf a where
-  erf :: a -> a
-  erfinv :: a -> a
+-- | @<@
+-- >>> 41 `lt` 42 :: Double
+-- 1.0
+--
+-- >>> 42 `lt` 42 :: Double
+-- 0.0
+--
+-- >>> 43 `lt` 42 :: Double
+-- 0.0
+lt :: SymOrd a => a -> a -> a
+lt x y = 1 - geq x y
+
+-- | @>@
+-- >>> 41 `gt` 42 :: Double
+-- 0.0
+--
+-- >>> 42 `gt` 42 :: Double
+-- 0.0
+--
+-- >>> 43 `gt` 42 :: Double
+-- 1.0
+gt :: SymOrd a => a -> a -> a
+gt x y = 1 - leq x y
+
+-- | @ifLeqThen x y ifX ifY == if x <= y then ifX else ifY@
+-- >>> ifLeqThen 41 42 100 200 :: Double
+-- 100.0
+--
+-- >>> ifLeqThen 42 42 100 200 :: Double
+-- 100.0
+--
+-- >>> ifLeqThen 43 42 100 200 :: Double
+-- 200.0
+--
+ifLeqThen :: SymOrd a => a -> a -> a -> a -> a
+ifLeqThen = ifCondThen leq
+
+
+-- | @ifGeqThen x y ifX ifY == if x >= y then ifX else ifY@
+-- >>> ifGeqThen 41 42 100 200 :: Double
+-- 200.0
+--
+-- >>> ifGeqThen 42 42 100 200 :: Double
+-- 100.0
+--
+-- >>> ifGeqThen 43 42 100 200 :: Double
+-- 100.0
+--
+ifGeqThen :: SymOrd a => a -> a -> a -> a -> a
+ifGeqThen = ifCondThen geq
+
+
+-- | @ifEqThen x y ifX ifY == if x == y then ifX else ifY@
+-- >>> ifEqThen 41 42 100 200 :: Double
+-- 200.0
+--
+-- >>> ifEqThen 42 42 100 200 :: Double
+-- 100.0
+--
+-- >>> ifEqThen 43 42 100 200 :: Double
+-- 200.0
+--
+ifEqThen :: SymOrd a => a -> a -> a -> a -> a
+ifEqThen = ifCondThen eq
+
+
+-- | @ifLtThen x y ifX ifY == if x < y then ifX else ifY@
+-- >>> ifLtThen 41 42 100 200 :: Double
+-- 100.0
+--
+-- >>> ifLtThen 42 42 100 200 :: Double
+-- 200.0
+--
+-- >>> ifLtThen 43 42 100 200 :: Double
+-- 200.0
+--
+ifLtThen :: SymOrd a => a -> a -> a -> a -> a
+ifLtThen = ifCondThen lt
+
+
+-- | @ifGtThen x y ifX ifY == if x > y then ifX else ifY@
+-- >>> ifGtThen 41 42 100 200 :: Double
+-- 200.0
+--
+-- >>> ifGtThen 42 42 100 200 :: Double
+-- 200.0
+--
+-- >>> ifGtThen 43 42 100 200 :: Double
+-- 100.0
+--
+ifGtThen :: SymOrd a => a -> a -> a -> a -> a
+ifGtThen = ifCondThen gt
+
+
+ifCondThen :: Num a => (a -> a -> a) -> a -> a -> a -> a -> a
+ifCondThen cond x y if' then' = true*if' + (1 - true)*then'
+  where
+    true = cond x y
diff --git a/tests/doctests.hs b/tests/doctests.hs
new file mode 100644
--- /dev/null
+++ b/tests/doctests.hs
@@ -0,0 +1,8 @@
+{-# OPTIONS_GHC -Wall #-}
+
+module Main where
+
+import Test.DocTest
+
+main :: IO ()
+main = doctest ["src/Casadi/Overloading.hs"]