diff --git a/LICENSE b/LICENSE
--- a/LICENSE
+++ b/LICENSE
@@ -1,30 +0,0 @@
-Copyright (c) 2014, The Hakaru Team
-
-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 The Hakaru Team 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/Sampler.hs b/Sampler.hs
new file mode 100644
--- /dev/null
+++ b/Sampler.hs
@@ -0,0 +1,26 @@
+{-# LANGUAGE RankNTypes #-}
+{-# OPTIONS -W #-}
+
+module Sampler (Sampler, deterministic, sbind, smap) where
+
+import Mixture (Mixture, mnull, empty, scale, point)
+import RandomChoice (choose)
+import System.Random (RandomGen)
+
+-- Sampling procedures that produce one sample
+
+type Sampler a = forall g. (RandomGen g) => g -> (Mixture a, g)
+
+deterministic :: Mixture a -> Sampler a
+deterministic m g = (m, g)
+
+sbind :: Sampler a -> (a -> Sampler b) -> Sampler b
+sbind s k g0 =
+  case s g0 of { (m1, g1) ->
+    if mnull m1 then (empty, g1) else
+      case choose m1 g1 of { (a, v, g2) ->
+        case k a g2 of { (m2, g) ->
+          (scale v m2, g) } } }
+
+smap :: (a -> b) -> Sampler a -> Sampler b
+smap f s = sbind s (\a -> deterministic (point (f a) 1))
diff --git a/hakaru.cabal b/hakaru.cabal
--- a/hakaru.cabal
+++ b/hakaru.cabal
@@ -2,7 +2,7 @@
 -- documentation, see http://haskell.org/cabal/users-guide/
 
 name:                hakaru
-version:             0.1.1
+version:             0.1.2
 synopsis:            A probabilistic programming embedded DSL
 description:         Hakaru is an embedded DSL for performing probabilistic inference. It supports multiple inference backends.
 homepage:            http://www.indiana.edu/~ppaml
@@ -17,7 +17,7 @@
 cabal-version:       >=1.10
 
 library
-  exposed-modules:     Types, Visual, Language.Hakaru.Syntax, Mixture, Language.Hakaru.Symbolic, RandomChoice, Util.Extras, Util.Coda, Examples.Tests, Language.Hakaru.ImportanceSampler, Language.Hakaru.Metropolis
+  exposed-modules:     Sampler, Types, Visual, Language.Hakaru.Syntax, Mixture, Language.Hakaru.Symbolic, RandomChoice, Util.Extras, Util.Coda, Examples.Tests, Language.Hakaru.ImportanceSampler, Language.Hakaru.Metropolis
   -- other-modules:       
   other-extensions:    RankNTypes, BangPatterns, OverloadedStrings, TypeFamilies, ConstraintKinds, GADTs, FlexibleContexts, TypeOperators, DataKinds, NoMonomorphismRestriction, DeriveDataTypeable, ScopedTypeVariables, ExistentialQuantification, StandaloneDeriving
   build-depends:       base >=4.6 && <4.7, aeson >=0.7 && <0.8, text >=1.1 && <1.2, bytestring >=0.10 && <0.11, pretty >=1.1 && <1.2, logfloat >=0.12 && <0.13, containers >=0.5 && <0.6, random >=1.0 && <1.1, math-functions >=0.1 && <0.2, vector >=0.10 && <0.11, cassava >=0.4 && <0.5, zlib >=0.5 && <0.6, statistics >=0.11 && <0.12, hmatrix >=0.16 && <0.17, parsec >=3.1 && <3.2