Judgment of the Court (Sixth Chamber) of 20 November 2003 in Case C-340/01 (Reference for a preliminary ruling from the Oberster Gerichtshof): Carlito Abler and Others v Sodexho MM Catering Gesellschaft mbH, intervener Sanrest Großküchen Betriebsgesellschaft mbH (Social policy — Approximation of laws — Transfers of undertakings — Safeguarding of workers' rights — Directive 77/187/EEC — Scope — Definition of transfer)