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diff --git a/docs/examples/pilib/handover.scala b/docs/examples/pilib/handover.scala
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+package examples.pilib;
+
+/**
+* Handover example with recursive types for channels.
+*/
+object handoverRecursive {
+
+  import concurrent.pilib._;
+
+  val random = new java.util.Random();
+
+  /**
+  * Recursive type for channels that carry a channel "unit" and
+  * an object of the type we define.
+  */
+  class Switch extends Chan[Pair[Chan[unit], Switch]];
+
+  /**
+  * Car.
+  */
+  def Car(talk: Chan[unit], switch: Switch): unit =
+    choice (
+      switch * ({ case Pair(t,s) => Car(t, s) }),
+      talk(()) * ( {
+	Thread.sleep(1 + random.nextInt(1000));
+	System.out.println("Car emitted a message.");
+	Car(talk, switch)
+      })
+    );
+
+  /**
+  * Control center.
+  */
+  def Control(talk1: Chan[unit], switch1: Switch,
+	      gain1: Switch, lose1: Switch,
+	      talk2: Chan[unit], switch2: Switch,
+	      gain2: Switch, lose2: Switch): unit
+  = {
+    def Control1: unit= {
+      Thread.sleep(1 + random.nextInt(1000));
+      lose1.write(Pair(talk2, switch2));
+      gain2.write(Pair(talk2, switch2));
+      Control2;
+    }
+    def Control2: unit = {
+      Thread.sleep(1 + random.nextInt(1000));
+      lose2.write(Pair(talk1, switch1));
+      gain1.write(Pair(talk1, switch1));
+      Control1;
+    }
+    Control1;
+  }
+
+  /**
+  * Active transmitter.
+  */
+  def ActiveTransmitter(id: String, talk: Chan[unit], switch: Switch,
+	    gain: Switch, lose: Switch): unit
+  =
+    choice (
+      talk * (x => {
+	System.out.println(id + " received a message.");
+	ActiveTransmitter(id, talk, switch, gain, lose)
+      }),
+      lose * ({ case Pair(t, s) => {
+	switch.write(Pair(t, s));
+	IdleTransmitter(id, gain, lose)
+      }})
+    );
+
+  /**
+  * Idle transmitter.
+  */
+  def IdleTransmitter(id: String, gain: Switch, lose: Switch): unit = {
+    val Pair(t, s) = gain.read;
+    ActiveTransmitter(id, t, s, gain, lose)
+  }
+
+  def main(args: Array[String]): unit = {
+    val talk1 = new Chan[unit];
+    val switch1 = new Switch;
+    val gain1 = new Switch;
+    val lose1 = new Switch;
+    val talk2 = new Chan[unit];
+    val switch2 = new Switch;
+    val gain2 = new Switch;
+    val lose2 = new Switch;
+    spawn <
+    Car(talk1, switch1) |
+    ActiveTransmitter("Transmitter 1", talk1, switch1, gain1, lose1) |
+    IdleTransmitter("Transmitter 2", gain2, lose2) |
+    Control(talk1, switch1, gain1, lose1, talk2, switch2, gain2, lose2)
+    >
+  }
+}
+
+/**
+* Handover example with type casts.
+*/
+object handoverCast {
+
+  import concurrent.pilib._;
+
+  val random = new java.util.Random();
+
+  /**
+  * Car.
+  */
+  def Car(talk: Chan[Any], switch: Chan[Any]): unit =
+    choice (
+      switch * (o => {
+        val Pair(t,s) = o.asInstanceOf[Pair[Chan[Any],Chan[Any]]];
+	Car(t, s)
+      }),
+      talk(()) * ( {
+	Thread.sleep(1 + random.nextInt(1000));
+	System.out.println("Car emitted a message.");
+	Car(talk, switch)
+      })
+    );
+
+  /**
+  * Control center.
+  */
+  def Control(talk1: Chan[Any], switch1: Chan[Any],
+	      gain1: Chan[Any], lose1: Chan[Any],
+	      talk2: Chan[Any], switch2: Chan[Any],
+	      gain2: Chan[Any], lose2: Chan[Any]): unit
+  = {
+    def Control1: unit= {
+      Thread.sleep(1 + random.nextInt(1000));
+      lose1.write(Pair(talk2, switch2));
+      gain2.write(Pair(talk2, switch2));
+      Control2
+    }
+    def Control2: unit = {
+      Thread.sleep(1 + random.nextInt(1000));
+      lose2.write(Pair(talk1, switch1));
+      gain1.write(Pair(talk1, switch1));
+      Control1
+    }
+    Control1
+  }
+
+  /**
+  * Active transmitter.
+  */
+  def ActiveTransmitter(id: String, talk: Chan[Any], switch: Chan[Any],
+			gain: Chan[Any], lose: Chan[Any]): unit
+  =
+    choice (
+      talk * (x => {
+	System.out.println(id + " received a message.");
+	ActiveTransmitter(id, talk, switch, gain, lose)
+      }),
+      lose * (o => {
+	val Pair(t, s) = o.asInstanceOf[Pair[Chan[Any],Chan[Any]]];
+	switch.write(Pair(t, s));
+	IdleTransmitter(id, gain, lose)
+      })
+    );
+
+  /**
+  * Idle transmitter.
+  */
+  def IdleTransmitter(id: String, gain: Chan[Any], lose: Chan[Any]): unit = {
+    val Pair(t, s) = gain.read.asInstanceOf[Pair[Chan[Any],Chan[Any]]];
+    ActiveTransmitter(id, t, s, gain, lose)
+  }
+
+  def main(args: Array[String]): unit = {
+    val talk1 = new Chan[Any];
+    val switch1 = new Chan[Any];
+    val gain1 = new Chan[Any];
+    val lose1 = new Chan[Any];
+    val talk2 = new Chan[Any];
+    val switch2 = new Chan[Any];
+    val gain2 = new Chan[Any];
+    val lose2 = new Chan[Any];
+    spawn <
+    Car(talk1, switch1) |
+    ActiveTransmitter("Transmitter 1", talk1, switch1, gain1, lose1) |
+    IdleTransmitter("Transmitter 2", gain2, lose2) |
+    Control(talk1, switch1, gain1, lose1, talk2, switch2, gain2, lose2)
+    >
+  }
+
+}
+
+