code: public void setExpression(Expression newExpression)
    {
      if (newExpression != expression)
      {
        NotificationChain msgs = null;
        if (expression != null)
          msgs = ((InternalEObject)expression).eInverseRemove(this, EOPPOSITE_FEATURE_BASE - SimpleExpressionsPackage.NOT_EXPRESSION__EXPRESSION, null, msgs);
        if (newExpression != null)
          msgs = ((InternalEObject)newExpression).eInverseAdd(this, EOPPOSITE_FEATURE_BASE - SimpleExpressionsPackage.NOT_EXPRESSION__EXPRESSION, null, msgs);
        msgs = basicSetExpression(newExpression, msgs);
        if (msgs != null) msgs.dispatch();
      }
      else if (eNotificationRequired())
        eNotify(new ENotificationImpl(this, Notification.SET, SimpleExpressionsPackage.NOT_EXPRESSION__EXPRESSION, newExpression, newExpression));
    }
docs: <!-- begin-user-doc -->
  <!-- end-user-doc -->
  @generated