<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
               assembly="CircularTest"
               namespace="CircularTest">

  <class name ="A" table ="ATable">

    <!-- Id -->
    <id name ="Id" type ="Guid">
      <generator class ="guid.comb"/>
    </id>

    <!-- Data -->
    <property name ="Data"/>

    <!-- Areference -->
    <property name ="Areference" />

  </class>

</hibernate-mapping>

namespace CircularTest
{
    public class A
    {
        public virtual Guid Id { get; set; }
        public virtual int Data { get; set; }
        public virtual A Areference { get; set; }
    }
}