diff --git a/lib/Doctrine/ORM/Query/AST/AggregateExpression.php b/lib/Doctrine/ORM/Query/AST/AggregateExpression.php
index 13d283233..b533eaa18 100644
--- a/lib/Doctrine/ORM/Query/AST/AggregateExpression.php
+++ b/lib/Doctrine/ORM/Query/AST/AggregateExpression.php
@@ -24,7 +24,13 @@ namespace Doctrine\ORM\Query\AST;
 /**
  * Description of AggregateExpression
  *
- * @author robo
+ * @license http://www.opensource.org/licenses/lgpl-license.php LGPL
+ * @link    www.doctrine-project.org
+ * @since   2.0
+ * @version $Revision: 3938 $
+ * @author  Guilherme Blanco <guilhermeblanco@hotmail.com>
+ * @author  Jonathan Wage <jonwage@gmail.com>
+ * @author  Roman Borschel <roman@code-factory.org>
  */
 class AggregateExpression extends Node
 {
diff --git a/lib/Doctrine/ORM/Query/AST/ArithmeticExpression.php b/lib/Doctrine/ORM/Query/AST/ArithmeticExpression.php
index 8c969cd45..fcf0b0855 100644
--- a/lib/Doctrine/ORM/Query/AST/ArithmeticExpression.php
+++ b/lib/Doctrine/ORM/Query/AST/ArithmeticExpression.php
@@ -1,7 +1,22 @@
 <?php
-/* 
- * To change this template, choose Tools | Templates
- * and open the template in the editor.
+/*
+ *  $Id$
+ *
+ * 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.
+ *
+ * This software consists of voluntary contributions made by many individuals
+ * and is licensed under the LGPL. For more information, see
+ * <http://www.doctrine-project.org>.
  */
 
 namespace Doctrine\ORM\Query\AST;
@@ -9,47 +24,27 @@ namespace Doctrine\ORM\Query\AST;
 /**
  * ArithmeticExpression ::= SimpleArithmeticExpression | "(" Subselect ")"
  *
- * @author robo
+ * @license http://www.opensource.org/licenses/lgpl-license.php LGPL
+ * @link    www.doctrine-project.org
+ * @since   2.0
+ * @version $Revision: 3938 $
+ * @author  Guilherme Blanco <guilhermeblanco@hotmail.com>
+ * @author  Jonathan Wage <jonwage@gmail.com>
+ * @author  Roman Borschel <roman@code-factory.org>
  */
 class ArithmeticExpression extends Node
 {
-    private $_simpleArithmeticExpression;
-    private $_subselect;
-
-    public function setSimpleArithmeticExpression($simpleArithmeticExpr)
-    {
-        if ($this->_subselect) {
-            throw \Doctrine\Common\DoctrineException::updateMe();
-        }
-        $this->_simpleArithmeticExpression = $simpleArithmeticExpr;
-    }
-
-    public function setSubselect($subselect)
-    {
-        if ($this->_simpleArithmeticExpression){
-            throw \Doctrine\Common\DoctrineException::updateMe();
-        }
-        $this->_subselect = $subselect;
-    }
-
-    public function getSimpleArithmeticExpression()
-    {
-        return $this->_simpleArithmeticExpression;
-    }
-
-    public function getSubselect()
-    {
-        return $this->_subselect;
-    }
+    public $simpleArithmeticExpression;
+    public $subselect;
 
     public function isSimpleArithmeticExpression()
     {
-        return (bool) $this->_simpleArithmeticExpression;
+        return (bool) $this->simpleArithmeticExpression;
     }
 
     public function isSubselect()
     {
-        return (bool) $this->_subselect;
+        return (bool) $this->subselect;
     }
 
     public function dispatch($sqlWalker)
diff --git a/lib/Doctrine/ORM/Query/Parser.php b/lib/Doctrine/ORM/Query/Parser.php
index fed0757b6..04f1582c3 100644
--- a/lib/Doctrine/ORM/Query/Parser.php
+++ b/lib/Doctrine/ORM/Query/Parser.php
@@ -1900,14 +1900,14 @@ class Parser
 
             if ($peek['type'] === Lexer::T_SELECT) {
                 $this->match('(');
-                $expr->setSubselect($this->Subselect());
+                $expr->subselect = $this->Subselect();
                 $this->match(')');
 
                 return $expr;
             }
         }
 
-        $expr->setSimpleArithmeticExpression($this->SimpleArithmeticExpression());
+        $expr->simpleArithmeticExpression = $this->SimpleArithmeticExpression();
 
         return $expr;
     }
diff --git a/lib/Doctrine/ORM/Query/SqlWalker.php b/lib/Doctrine/ORM/Query/SqlWalker.php
index 5b5a9a5ee..77b8fc5a6 100644
--- a/lib/Doctrine/ORM/Query/SqlWalker.php
+++ b/lib/Doctrine/ORM/Query/SqlWalker.php
@@ -30,7 +30,6 @@ use Doctrine\ORM\Query,
  *
  * @author Roman Borschel <roman@code-factory.org>
  * @since 2.0
- * @todo Code review for identifier quoting.
  * @todo Code review for schema usage with table names.
  *       (Prepend schema name to tables IF schema is defined AND platform supports them)
  */
@@ -1272,17 +1271,9 @@ class SqlWalker implements TreeWalker
      */
     public function walkArithmeticExpression($arithmeticExpr)
     {
-        $sql = '';
-        
-        if ($arithmeticExpr->isSimpleArithmeticExpression()) {
-            foreach ($arithmeticExpr->getSimpleArithmeticExpression()->getArithmeticTerms() as $term) {
-                $sql .= $this->walkArithmeticTerm($term);
-            }
-        } else {
-            $sql .= $this->walkSubselect($arithmeticExpr->getSubselect());
-        }
-        
-        return $sql;
+        return ($arithmeticExpr->isSimpleArithmeticExpression())
+        	? $this->walkSimpleArithmeticExpression($arithmeticExpr->simpleArithmeticExpression)
+        	: $this->walkSubselect($arithmeticExpr->subselect);
     }
 
     /**